Title of Invention

MACROLIDE ANTIINFECTIVE AGENTS

Abstract Compounds of formula (1), (2) or (3), wherein Ra is H; substituted or unsub- stituted alkyl (1-10C); substituted or un- substituted alkenyl (2-10C); substituted or unsubstituted alkynyl (2-10C); substituted or unsubstituted aryl (4-14C); substituted or unsubstituted arylalkyl (5-20C); or ORa is replaced by H; Rb is H or halogen; Rc is H or a protecting group; Rd is methyl, unsubstituted alkyl (3-10C); substituted alkyl (1-10C); substituted or unsubstituted alkynyl (2-10C); substituted or unsubsti- tuted aryl (4-14C); substituted or unsub- stituted arylalkyl (5-20C); substituted or unsubstituted arylalkenyl (5-20C); substi- tuted or unsubstituted arylalkynyl (5-20C); substituted or unsubstituted amidoarylalkyl (5-20C); substituted or unsubstituted ami- doarylalkenyl (5-20C); or substituted or unsubstituted amidoarylalkynyl (5-20C); Rc is H or a protecting group; L is methylene or carbonyl; T is -O-, -N(R)-, -N(OR)-, -N(NHCOR)-, -N(N-CHR)-, or -N(NHR)- wherein R is H or Ra as de- fined above, with the proviso that when L is methylene, T is -O-; one of Z and Y is H and the other is OH, protected OH, or amino, mono- or dialkylamino, protected amino, or an amino heterocycle or Z and Y together are -O, -NOH or a derivatized oxime; including any pharmaceutically acceptable salts thereof and any stereoisomeric forms and mixtures of stereoisomeric forms thereof, are antimicrobial agents.
Full Text MACROLIDE ANTIINFECTIVE AGENTS
Technical Field
The invention is-directed to antibacterial compounds that expand the repertoire of
erythromycin-like antibiotics. More particularly,the invention concerns macrolide
antibiotics containing an erythronolide nucleus modified at least at the substituent
at C-13.
Background Art
The increasing number of microbial strains that have acquired resistance to the
currently available known antibiotic compounds is recognized as a dangerous threat to
public health. As the use of such compounds has proliferated,so too has the need for
expanding the options available to treat a wide variety of microbial-based conditions.
The need for a larger choice of antimicrobial compounds extends beyond treatment of
human infection and to a need to preserve food and other perishable commodities. New
antibiotics can also be essential for resistant plants and animals as well as to provide
resistance to materials that otherwise are subject to microbially caused corrosion.
Thus,there is a clear need for an expanded armament of compounds which can
provide a multifaceted defense against unwanted microbial activity.
PCT Publication No. WO 98/09978 published 12 March 1998 and incorporated
herein by reference discloses modified forms of erythromycin which lack a cladinose
residue at the 3-position and which are derivatized in various ways in positions 9-12 of
the macrolide ring. Similarly,U.S. Patent No. 5,750,510,issued 12 May 1998 and
incorporated herein by reference,discloses modified erythromycin derivatives.
The naturally occurring erythromycins have the structure

wherein R' can be H or OH and R" can be H or CH3.
All of the compounds disclosed in the above-referenced patent documents contain
an ethyl group at position 13 of the macrolide ring. The present inventors have found that
alterations in the substituent at position 13 results in a large number of compounds with
excellent antibacterial activity.
Disclosure of the Invention
The invention is directed to erythronolide derivatives that contain modifications
from the native structure. All of the compounds of Ihe invention are modified at least at
position 13 and have a ring at the 11,12 position.
The present invention provides a compound of the formula

or a pharmaceutically acceptable salt thereof wherein
Ra is substituted or unsubstituted aryl (4-14C); substituted or unsubstituted
arylalkyl (5-20C); substituted or unsubstituted arylalkenyl (5-20C); substituted or unsubstitute
arylalkynyl (5-20C);
Rb is H or halogen;
Rd is fluoroethyl; and
Rf is H or C1-C3 alkyl.
Thus,in one aspect,the invention is directed to compounds of the formula
wherein
Ra is H; substituted or unsubstituted alky] (1-10C); substituted or unsubstituted
alkenyl (2-10C); substituted or unsubstituted alkynyl (2-10C); substituted or unsubstituted
aryl (4-14C); substituted or unsubstituted arylalkyl (5-20C); or ORa may be replaced by
H;
Rb is H or halogen;
Rc is H or a protecting group;
Rd is methyl,unsubstituted alkyl (3-10C); substituted alkyl (1-10C); substituted or
unsubstituted alkenyl (2-10C); substituted or unsubstituted alkynyl; substituted or
unsubstituted aryl (4-14C); substituted or unsubstituted arylalkyl (5-20C); substituted or
unsubstituted arylalkenyl (5-20C); substituted or unsubstituted arylalkynyl (5-20C);
substituted or unsubstituted amidoarylalkyl (5-20C); substituted or unsubstituted
amidoarylalkenyl (5-20C); or substituted or unsubstituted amidoarylalkynyl (5-20C);
Rc is H or a protecting group;
L is methylene or carbonyl;
T is -O- ,-N(R)-,-N(OR)-,-N(NHCOR)-,-N(N=CHR)-,or -N(NHR)- wherein R
is H or Ra as defined above,with the proviso that when L is methylene,T is -O- ;
one of Z and Y is H and the other is OH,protected OH,or amino,mono- or
dialkylamino,protected amino,or an amino heterocycle or
Z and Y together are =O,=NOH or a derivatized oxime;
including any pharmaceutically acceptable salts thereof and any stereoisomeric
forms and mixtures of stereoisomeric forms thereof.
In another aspect,the invention is directed to pharmaceutical or preservative
compositions containing the compounds of formulas (l)-(3) and to methods to treat
infectious diseases by administering these compounds or to preserve materials by
providing them.

A Brief Description of the accompanyingDrawings
Figure 1 shows a schematic of the synthesis of intermediates for the compounds of
the invention.
Figure 2 shows a schematic of the synthesis of the compounds of the invention
from these intermediates.
Figure 3 shows a schematic of an alternate synthesis of the compounds of the
invention from the intermediate compound (7).
Figures 4a and 4b show a schematic of the synthesis of the compounds of the
invention.
Figure 5 shows a schematic of the synthesis of the inventive compounds wherein
T is -O- .
Figure 6 shows the post-PKS biosynthesis of erythromycins. This pathway is
employed in the present invention,as shown in Figure 1.
Figure 7 shows the synthesis of intermediate compounds of formula (4) wherein
Ra is methyl.
Figure 8 shows the synthesis of intermediate compounds of formula (6) and their
corresponding 10,11-anhydro forms.
Figure 9 shows the synthesis of intermediate compounds of formula (6) (anhydro
form) wherein ORa is replaced by H. .
Figure 10 illustrates the conversion of 15-azidoerythromycin A into 15-
amidoerythromycins.
Figure 11 illustrates the conversion of 15-amidoerythromycins into the
corresponding 15-amido-6-O- alkyl-ketolide 11,12-cyclic carbamates.
Figure 12 shows structures of particularly preferred examples of 15-amido-6-O- alkyl-ketolide 11,12-cyclic carbamates. In each case,X may be either H or F.
Figure 13 illustrates the conversion of 15-ethenylerythromycin A into the 15-
ethenyl-6-O-alkyl-ketolide 11,12-cyclic carbamates,as well as optional fluorination at
C2.
Figure 14 illustrates the attachment of aromatic groups onto the ethenyl moiety of
15-ethenylketolides to form 15-(2-arylethenyl)ketolides,and optional hydrogenation to
form the 15-(2-arylethyl)ketolides.
Figure 15 shows structures of particularly preferred examples of 15-(2-
arylethenyl)-6-O- methyl-ketolide 11,12-cyclic carbamates and 15-(2-arylethyl)-6-O- .
methyl-ketolide 11,12-cyclic carbamates. In each case,X may be either H or F.
Figure 16 shows the synthesis of 15-ethenyl ketolides via olefin metathesis.
Modes of Carrylng Out the Invention
The compounds of the invention are conveniently synthesized by combining
synthetic chemical techniques with microbiological processes involving genetically
engineered microorganisms. Briefly,in a preferred mode of carrylng out the invention,a
microbial host,preferably a host which does not itself produce a macrolide antibiotic,is
provided with a recombinant expression system for the production of modified
6-deoxyerythronolide B (6-dEB),which expression system in some instances will have
been altered by a disruption in the catalytic domain of the ketosynthase moiety in the first
module. For substituents in which Rd is methyl,host cells are used which do not have a
disrupted domain of the ketosynthase moiety. This alteration in the 6-dEB polyketide
synthase (PKS) results in the inability of this PKS to utilize its native starter unit,and
thus permits inclusion of a synthetic diketide thioester for its initial condensation product
in the sequence of reactions leading to modified 6-dEB without competition from the
diketide that would otherwise,natively,have been produced. Thus,the recombinant host
can be provided a synthetic diketide thioester for incorporation into the resulting
polyketide. The incorporation of this diketide into the resulting polyketide results in a
polyketide with a substituent at position 13 that may be selected as desired. Preferred
methods for preparing the synthetic polyketide thioesters are set forth in PCT Publication
No. WO 00/44717 which claims priority to copending Patent Application U.S. Serial No.
60/117,384 filed 27 January 1999 and 09/492,733 filed on 27 January 2000,which are
incorporated herein by reference.
Recombinant forms of the 6-dEB PKS containing inactivated ketosynthase (KS)
domains in the first module (KS1) and appropriate organisms modified to contain an
expression system for this PKS are described in PCT Publications WO 97/02358,
published 28 January 1997 and WO 99/03986,published 28 January 1999,incorporated
herein by reference.
The polyketide resulting from expression of the modified PKS is then isolated and
purified,if desired,from the recombinantly modified organism and fed to
Saccharopolyspora erythraea,which contains the functionality for postpolyketide
modifications,including glycosylation. Other modifications include hydroxylation at
positions 6 and 12. The resulting modified erythromycin is then isolated and chemically
modified to obtain the compounds of the invention. Synthetic methods for providing
these modifications are described in PCT Publication No. WO 98/09978 and U.S. Patent
No. 5,750,510,referenced hereinabove.
The general method for synthesizing intermediates to compounds of the invention
is shown in Figure 1.
The method for synthesizing compounds from intermediates of the invention is
shown in Figure 2.
The resulting antiinfective compound is active in vitro and in vivo for activity
against a panel of representative microorganisms. The compounds of the invention thus
exhibit a sufficient diversity in specificity to cover the spectrum of antibiotic activities
desired.
For use in treating infectious disease,the compounds of the invention are
formulated into suitable compositions which will include typical excipients,
pharmaceutically acceptable counterions if the compound is a salt,further additives as
desired,such as antioxidants,buffers,and the like,and adrninistered to animals or
humans. The types of formulations that are appropriate for these compounds are similar
to those for the macrolide antibiotics in general Formulations may be found,for
example,in Remington's Pharmaceutical Sciences. Mack Publishing Co.,latest edition.
The compounds can be administered by any desired route,including injection,oral
administration,transdermal administration,transmucosal administration,or any
combination. The compounds of the invention can also be administered with additional
active ingrethents if desired.
The compounds of the invention are of formulas (l)-(3) as set forth above,as well
as any stereoisomeric forms of these compounds as shown. The particular stereoisomers
depicted are those resulting from the preferred method of synthesis set forth above and
exemplified herein; however,by modifylng the expression system for the PKS,or by
altering the chirality of the diketide,or by synthetic chemical conversion,other
stereoisomers may also be prepared. Additional chiral centers may be present in the
substituents,such as Ra and Rd. The stereoisomers may be administered as mixtures,or
individual stereoisomers may be separated and utilized as is known in the art.
The properties of the compounds of formulas (l)-{3) are defined by the
substituents Ra-Rc,L,T,Y and Z. Preferred embodiments of these substituents are set
forth hereinbelow. They contain moieties which are defined as follows:
"Halogen" includes fluoro,chloro,bromo and iodo,and most preferably fluoro.
"Alkyl" refers to a saturated straight-chain,branched chain or cyclic hydrocarbyl
moiety containing a specified number of carbons and that may contain one or more
suitable heteroatoms; similarly,alkenyl and alkynyl refer to straight or branched chain or
cyclic hydrocarbon substituents containing one or more double bonds or one or more
triple bonds,respectively and that may contain one or more suitable heteroatoms.
"Aryl" refers to an aromatic substituent that may contain one or more suitable
heteroatoms such as phenyl,naphthyl,quinolyl,or phenanthryl.
"Arylalkyl," "arylalkenyl," or "arylalkynyl" refer to substituents wherein an aryl
group is linked to the substituted moiety through an alkyl,alkenyl or alkynyl linkage,
respectively. Again,the number of carbons in the arylalkyl,arylalkenyl or arylalkynyl
groups will be specified.
"Amidoarylalkyl," "amidoarylalkenyl," or "amidoarylalkynyl" refer to substituents
wherein an aryl group is linked to the substituted moiety through an amido and an alkyl,
alkenyl or alkynyl linkage,respectively. Again,the number of carbons in the
amidoarylalkyl,amidoarylalkenyl or amidoarylalkynyl groups will be specified.
Thus,included among the defined substituents herein are "heteroalkyl,"
"heteroalkenyl," "heteroalkynyl," "heteroaryl," "heteroarylalkyl," and the like. Suitable
heteroatoms include N,O,and S.
All of the foregoing substituents may be unsubstituted or may be further
substituted. Typical substituents include R,-OR,-SR,-NR2,-COR,-COOR,-CONR2,
-OOCR,-NRCOR,-OCONR2,-CN,-CF3,-NO2,-SOR,-SO2R,halogen wherein each R
is independently H or is alkyl,alkenyl,alkynyl,aryl,arylalkyl,or the hetero forms of
these as defined above. In addition, alkyl, alkenyl and alkynyl may be substituted by aryl
or heteroaryl, which may, themselves, be further substituted.
"A derivatized oxime" is of the formula =N-O- R, wherein R is other than H and is
otherwise defined as above.
A "protecting group" for a hydroxy includes acyl groups, silyl groups, and the like.
Suitable protecting groups are described by Greene, T.W., et al, in Protecting Groups in
Organic Synthesis, 2nd Ed., John Wiley & Sons, Inc. (1991), incorporated herein by
reference.
The invention includes more preferred embodiments of the compound defined
above. R4 is preferably butyl, pentyl, methoxyethoxymethyl, isobutyl, methylcyclohexyl,
phenyl, benzyl, ethylphenyl, 3-(benzyloxy)propyl, 2-(pyrimidin-2-ylthio)ethyl, propyl,
fluoroethyl, chloroethyl, vinyl, 3-butenyl, or azidoethyl and more preferably propyl,
fluorocthyl, chloroethyl, vinyl, 3-butenyl, or azidoethyl. PCT Publication No. WO
00/44717 which claims priority to U.S. Serial No. 60/117, 384 filed 27 January 1999 and
U.S. Serial No. 09/492, 733 filed 27 January 2000 both of which are incorporated herein
by reference describe various oligoketide thioesters, preferably diketide thioesters, that
can be incorporated at the C-13 position. Such diketide thioesters as described therein are
incorporated into the compounds of the invention and thus determine preferred Rd groups
at the C-13 position.
In another preferred embodiment, Ra is H or lower C1-C3 alkyl, and more
preferably methyl. Ra is also preferably arylalkenyl or arylalkynyl such as 3-arylprop-2-
cnyl or 3-arylprop-2-ynyl. Preferably the aryl :group in the preferred arylalkenyl or
arylalkynyl embodiments are 3-quinolyl, 4-quinolyl, 5-quinolyl, phenyl, 4-fluorophenyl,
4-chlorophenyl, 4-methoxyphenyl, 6-quinolyl, 6-quinoxalyl, 6-amino-3-quinolyl, or 4-
isoquinolyl.
When T-L-0 forms a carbamate ring, a combination of substituents on the
carbamate nitrogen (R), the 6-0 position (Ra), and the 13 position (Rd) are especially
preferred. In a first preferred combination, Ra is preferably arylalkyl, arylalkenyl or
arylalkynyl; R is preferably H or substituted or unsubstituted lower alkyl; and Rd is
preferably substituted or unsubstituted alkyl. In these compounds Ra is more preferably
arylpropyl, arylprop-2-enyl, or arylprop-2-ynyl; R is more preferably hydrogen or methyl;
and Rd is more preferably propyl, fluoroethyl, or chloroethyl.
In a second preferred combination, Ra is H or substituted or unsubstituted lower
alkyl; R is preferably arylalkyl, arylalkenyl or arylalkynyl; and Rd is substituted or
unsubstituted alkyl. In these compounds, Ra is more preferably methyl; R is more
preferably arylpropyl, arylprop-2-enyl, or arylprop-2-ynyl; and Rd is more preferably
propyl, fluoroethyl, or chloroethyl.
In a third preferred combination, when Rd is an unsaturated substituent available
for further derivatization such as alkenyl or alkynyl or other group such as azidoalkyl,
then preferably Ra is H or substituted or unsubstituted lower alkyl, and R is H or
substituted or unsubstituted lower alkyl. Ra is more preferably H or methyl and R is more
preferably H. Illustrative unsaturated substituents, Rd are more preferably vinyl, propargyl,
or butenyl, and other derivatizable substituents include azidoethyl. These
compounds can be readily derivatized by the methods of the invention to form from the
unsaturated substituents the arlylkyl, arylalkenyl, or arylalkynyl substituents and from the
azido substituent the amidoarylalkyl, amidoarylakenyl, or amidoarylakynyl substituent
Preferred 15-amido ketolides, 15-ethenyl ketolides and other preferred
arylsubstituted ketolides are shown in Figures 12 and 15.
Further, in one embodiment of compound (1) T is not N(R). In another
embodiment of compound (1) T-L-O does not form a carbamate ring.
Synthesis of the Invention Compounds
As described above, the antibiotic starting materials for any further chemical
synthesis are prepared, preferably, by feeding a suitable diketide to a microorganism
modified to contain an expression system for the 6-dEB PKS containing a KS1 knockout,
or by a host cell that provides a methyl at the 13-position, followed by providing the
resulting polyketide to a recombinant strain of Saccharopolyspora erythraea that has
been altered to eliminate production of 6-dEB. A strain can be prepared that is able to
hydroxylate both the 6- and 12-positions or the 12-position only. In the latter case, -ORa
is replaced by -H. The recombinant S. erythraea strain, K40-67, is obtained by
transforming an S. erythraea strain that produces high levels of erythromycin A with a
plasmid comprising a mutated eryAl sequence encoding an inactivated KS1 domain. By
homologous recombination, the resulting transformants now are unable to produce 6-dEB
as a competitor to the substrate polyketide and, instead, hydroxylate the 6-position and
12-position and glycosylate the 3-position and 5-position of the modified polyketide that
has been made in Streptomyces or other polyketide-producing transformant. If a
macrolide having only the 12-position, and not the 6-position hydroxylated is desired
(ORa is replaced by H), an S. erythraea strain is constructed by disrupting the eryF
hydroxylase gene in strain K40-67. Alternatively, the eryK gene can be disabled, wherein
embodiments of compounds (l)-(3) may readily be produced.
Formation of the compounds of formulas (l)-(3) requires the production of the
erythronolide having a hydroxyl at the 12-position. The starting material may include any
of the compounds (4)-(6):
The glycosylation reactions for the production of the erythromycins result in the
diglycosylated forms analogous to the compounds set forth in formula (4) herein. If the
compounds of formula (4) are to be prepared from the initial product, the hydroxyl group
of the cladinose ring (attached to position 3) may then need to be protected for subsequent
modification of the macrolide substituents.
The modified erythromycins of the invention, in addition to modification at C-13,
contain an -OH group at position 6 unless ORa is replaced by H as described above. To
construct, ultimately, the compounds of formulas (1), (2) and (3) where position 6 is ORa,
the compound of formula (1) (see Figure 1) is provided with protecting groups which
form one embodiment of Rc and Rc. Such protection is effected using suitable protecting
reagents such as acetic anhydride, benzoic anhydride, benzochloro formate,
hexamethyldisilazane, or a trialkylsilyl chloride in an aprotic solvent. Aprotic solvents
include, for example, dichloromethane, chloroform, tetrahydrofuran, N-methyl
pyrrolidone, dimethyl sulfoxide (DMSO), dimethyl formamide (DMF) and the like.
Mixtures may also be used. Protection of both sugar hydroxyls in formula (I) may be
done simultaneously or sequentially.
In addition to protecting the 2' and 4" hydroxyl groups of the two glycose residues,
the keto group at position 9 of the macrolide ring must also be protected. Typically, this
is effected by converting the keto group to a derivatized oxime. Particularly preferred
embodiments for R in the formula =NOR include unsubstituted or substituted alkyl
(1-12C), substituted or unsubstituted aryl (6-10C), alkyl (1-12C), substituted or
unsubstituted heteroaryl (6-IOC), alkyl (1-12C), and heteroalkyl (such as substituents of
the formula CR'2OR wherein each R', in addition to being independently embothed as R
as set forth above, may, together with the other, form a cycloalkyl ring (3-12C)). A
preferred derivatized oxime is of the formula =NOR wherein R is isopropoxycyclohexyl.
With the 9-keto group and the 2' and 4" hydroxyls protected, it is then possible to
alkylate tlie 6-hydroxy group in the compound of formula (I) by reaction with an
alkylating agent in the presence of base. Alkylating agents include alkyl halides and
sulfonates. For example, the alkylating agents may include methyl tosylate, 2-fluoroethyl
bromide, cinnamyl bromide, crotonyl bromide, allyl bromide, propargyl bromide, and the
like. The alkylation is conducted in the presence of base, such as potassium hydroxide,
sodium hydride, potassium isopropoxide, potassium t-butoxide, and an aprotic solvent
The choice of alkylating agent will depend on the nature of the substituents Ra to
be included. As set forth above, Ra can be substituted or unsubstituted alkyl (1-10C),
substituted or unsubstituted alkenyl (2-10C), or substituted or unsubstituted alkynyl
(2-10C). Particularly preferred axe unsubstituted alkyl, alkenyl, or alkynyl, or substituted
forms of these wherein the substituents include one or more halogen, hydroxy, alkoxy
(1-6C), oxo, SO2R (1-6C), N3, CN, and NR2 wherein R is H, substituted or unsubstituted
alkyl (including cycloalkyl) (1-12C), substituted or unsubstituted alkenyl (including
cycloalkenyl) (2-12C), alkynyl (including cycloalkynyl) (2-12C), substituted or
unsubstituted aryl (6-10C), including the hetero forms of the above.
Especially preferred are methyl, allyl and ethyl.
Once the alkylation of the 6-hydroxyl is completed, the sugar residues and the
macrolide ring may be deprotected. Deprotection of the glycoside moieties is conducted
as described by Green, T.W., et al., in Protective Groups in Oreanic Synthesis, infra.
Similar conditions result in converting the derivatized oxime to =NOH. If formation of
the underivatized oxime is not concurrent with deprotection, the conversion to the oxime
is conducted separately.
The oxime can then be removed and converted to a keto group by standard
methods known in the art. Deoximating agents include inorganic sulfur oxide
compounds such as sodium hydrogen sulfite, sodium pyrosulfate, sodium thiosulfatc, and
the like. In this case, protic solvents are used, such as water, methanol, ethanol,
isopropanol, trimethyl silanol and mixtures of these. In general, the deoximation reaction
is conducted in the presence of an organic acid.
At this point in the process, or later, after the compound of formula (4) has been
converted to the compounds of formulas (5) or (6) or to any of compounds (l)-(3), as
further described below, the group introduced at the 6-hydroxyl can further be
manipulated. Conveniently, the initial substitution may provide a 6-O-allyl, i.e.,
O-CH2CH=CH2, which can further be derivatized by reduction to give the 6-0 propyl
compound, or be treated with osmium tetroxide to provide the 2, 3-dihydroxypropyl
compound, which can further be esterified at each oxygen atom. The O-allyl derivative
can also be oxidized with m-chloroperoxybenzoic acid in an aprotic solvent to provide
the epoxy compound which can be opened with amines or N-containing heteroaryl
compounds to provide compounds with N-containing side-chains, or can be oxidized
under Wacker conditions to provide the substituent O-CH2-C(O)-CH3, or can be ozonized
to provide the aldehyde. The aldehyde can then be converted to the oxime or reacted with
a suitable amine and reduced in the presence of a borohydride reducing agent to provide
an amine. The oxime can also be converted to a nitrile by reaction wim a dehydration
agent in an aprotic solvent The O-allyl derivative can also be reacted with an aryl halide
under Heck conditions (Pd(II) or Pd(O), phosphine and amine or inorganic base) to
provide a 3-aryl prop-2-enyl derivative. This derivative can then be reduced with
hydrogen and palladium on carbon to provide a 3-arylpropyl derivative. If the initial
substituent Ra is a 2-propyne, similar reactions can be employed to provide alterations in
the side-chain, including arylation.
In order to convert the compound of formula (4) into the compound of formula
(6), by first removing the cladinose moiety, the compound of formula (4) is treated with
mild aqueous acid or with a deglycosylating enzyme. Suitable acids include hydrochloric,
sulfuric, chloroacetic, trifluoroacetic and the like, in the presence of alcohol. Reaction
times are typically 0.5-24 hours at a temperature of -10-35°C During this reaction, the 2'
group of the remaining sugar is protected as set forth above and deprotected subsequent
to the decladinizing reaction. The resulting hydroxyl group at the 3-position of the
macrolide ring is then oxidized to the ketone using a modified Swern oxidation
procedure. In this procedure, an oxidizing agent such as N-chlorosuccinimide-dimethyl
sulfide or a carbodiamide-dimethylsulfoxide. is used. Typically, a compound of formula
(4) is added to pre-formed N-chlorosuccvnimide and dimethyl sulfide complex in a
chlorinated solvent such as methylene chloride at -10-25°C. After being stirred for 0.5-4
hours, a tertiary amine such as triemylamine is added to produce the corresponding
ketone and the 2' protecting group is then removed.
In order to halogenate the macrolide at position 2 (converting Rb=H to halogen),
the compound of formula (6), where Rb=H, is treated with a base and an electrophilic
halogenating reagent such as pyridinium perbromide or N-fluorobenzenesulfonimide.
Position 2 can be halogenated at any time after the 3 kcto compound is prepared and
preferably after the 11, 12 ring is formed.
The appropriate substituent such as vinyl, ethenyl, butenyl or azido at the C-13
position can be further manipulated. For example, an amidoacetate salt of the compound
of the invention can be derivatized using an arylacetyl chloride to yleld an arylamino
alkyl group on the C-13 position as illustrated in Figure 10. Preferably the C13
derivatives of an azido group take place before the ketolide is formed. Derivations of an
alkenyl group such as ethenyl can take place either before or after the ketolide is formed
and preferably after the 11, 12 ring is formed, as shown in Figures 14 and 16.
in order to obtain the compounds of formula (5), the compound resulting from the
deglycosylation reaction of formula (4) is treated with a dehydrating agent such as
carbonyl diimidazole and base.
Intermediates (7)-(9) can then be prepared from intermediates (4)-(6).
It will be noted that the presence of the 12-hydroxyl group is required. The
hydroxyl groups of the sugar moieties are protected as described above and the resulting
protected compounds arc then reacted with sodium hexamethyldisilazide and
carbonyldiimidazole which results in dehydration to obtain a ir-bond at position 10-11
and derivatization of the 12-hydroxyl to provide functionality in the macrolide ring as
shown in compounds (7)-(9). Figure 2 illustrates the reaction sequence from compound
(4) to compound (9) in the first step.
Reaction of compounds (7)-(9) with aqueous ammonia provides a compound of
formulas (l)-(3) wherein L is carbonyl and T is NH as shown in Figure 2 for compounds
(9) and (3) in the second step.
Reaction of compounds (7)-(9) with compounds of the formulas H2NR, H2NOR,
H2NNHCOR, H2NN=CHR or H2NNHR, where R is H or Ra, provides the corresponding
compounds of formulas (l)-(3) wherein T is nitrogen derivatized as described with the Rf
substituents including -R, -OR, -NHCOR, -N=CHR or -NHR. In Figure 2, Rf is H
because ammonia is used. These are compounds of the formulas (10)-(12):
where Rf represents the substituents on the nitrogen as described above. Figure 3
analogously depicts the reaction of compound (7) with H2NRf to form compound (10).
The preparation follows the procedure described by Baker et al. J Org Chem (1988)
53:2340, which is incorporated herein by reference. In particular, treatment of compound
(7) with an amino compound of the formula H2N-Rf results in formation of the cyclic
carbamate in which Rf is as described above. The protected 2'-hydroxy group can be
deprotected as described above.
Alternate or additional procedures may be used to prepare compounds (10)-(12)
where Rf is not H.
For example, the compounds of formulas (10)-(12) wherein Rf is H can be reacted
with an alkylating agent which is of the formula R-halogen to replace the hydrogen on the
ring nitrogen with an alkyl group.
Further, compounds (10)-(12) that do not contain an acyl group as a substituent on
the nitrogen of T can be formed by treatment of such compounds (10)-(12) with an
acylating agent selected from the group consisting of R(CO)-halogen or (RCO)2O to give
compounds (7)-(9) wherein T is -N- and Rf is -NH-COR.
Treatment of compounds (10)-(l 2) where Rf is -NH2 with an aldehyde R-CHO,
wherein R is as defined previously gives compounds (10)-(12) wherein Rf is -N=CHR.
Treatment of compounds (10)-(12), where Rf is -NH2 with an alkylating agent
having the formula R-halogen, wherein R is as defined previously, gives the compounds
(10K12) where Rf is R.
Of course, if the substrate for the ring formation is a compound of formula (4), a
compound of the formula (3) results; modifications can then be conducted to convert the
compound of formula (3) to compounds of formulas (1) and (2), as described above.
Under these circumstances, the keto group would be protected by a derivarized oxime.
Such modifications include removal of the cladinose moiety by acid hydrolysis; oxidizing
the 3-hydroxyl group; and deprotecting the protected hydroxyl and keto groups.
According to the alternate procedure shown in Illustrated Scheme 4a (Figure 4a),
the intermediate compound (10, which is the 9-oxime compound of erythromycin A, is
subjected to acid hydrolysis with dilute mineral or organic acid as described previously to
remove the cladinose moiety and give intermediate compcund (I:). The oxime compound
(I2) is then converted to the protected oxime compound (I3) wherein V is =N-O- Rl where
R1 is a protecting group, by reaction with the appropriately substituted oxime protecting
reagent. The 3 and 2'-hydroxy groups of (I3) are then protected, preferably with a
trimethylsilyl protecting group, to give compound (I4). Compound (I4) is then alkylated
as described previously to give compound (I5), and compound (I5) is first deoximated as
described above then the deoximated product is converted to the compound (I6) by the
procedures described for preparation of compound (3) from compound (4) in Illustrated
Scheme 2. Figure 4b shows compound (I6) is then deprotected and oxidized to the
3-ketolide derivative, compound (10) of the invention, wherein L is CO and T is -NRf by
procedures described previously. Intermediate compound I6 can also be deprotected and
dehydrated to form compound (11) of the invention, also shown in Figure 4b.
As mentioned earlier, the 6-position substituent can be manipulated after the
compounds (l)-(3) are formed. For example, compound (10) can be prepared wherein Ra
is -CH2-CH-N-ORh and Rh is H or C1-C3-alkyl, aryl substituted C1-C3-alkyl, orheteroaryl
substituted C1-C3-alkyl. In this method, compound (10), wherein Ra is -CH2-CH=CH2, is
treated with ozone to form compound (10) wherein Ra is -CH2-CH=O.
The compound (10) wherein Ra is -CH2-CH=O is further treated with a
hydroxylamine compound having the formula NH2-O- Rh, wherein Rh is as previously
defined; and optionally deprotecting, and isolating the desired compound. In a preferred
embodiment of the process immediately above, Rr is H.
In another embodiment of the invention is a process for preparing a compound
(10) wherein Ra is -CH2-CH2-NH-Rj where Ri, with the atom to which it is attached, form
a 3-10 membered substituted or unsubstituted heterocycloalkyl ring.
The method comprises reductively animating compound (10) wherein Ra is
-CH2-CH=O with an amine compound having the formula -NH2-Ri, wherein Ri is as
previously defined; and optionally deprotecting, and isolating the desired compound.

Compounds of the formulas (l)-(3) where L is carbonyl and T is -O- or wherein L
is methylene and T is -O- , are prepared from compounds (4)-(6) using the procedure
described by Baker et al, J Org Chem (1988) 53:2340 which is incorporated herein by
reference. The 2' or 2', 4"-protected compounds of formulas (4)-(6) are first converted to
the cyclic carbonates by reaction with carbonyldiimidazole and sodium
hexamethyldisilazide.
Compounds (13)-(15) represent compounds (l)-(3) where L is methylene and T is
-O- :

Illustrative Scheme 5 in Figure 5 illustrates the conversion of the compound
having formula (6) to the compound having the formula (1). Figures 11 and 13 illustrate
the conversion of erythromycins to ketolides.
In order to prepare compounds of formulas (4)-(6) or (l)-(3) wherein one of Z and
Y is H and the other OH or protected OH or is an amino derivative as described above,
either the carbonyl or oxime or derivatized oxime is reduced using a suitable reducing
agent. Substituted amines are obtained by alkylation.
Novel methods of synthesis of the compounds of the invention are also provided.
Exemplary Embodiments
The compounds of formulas (1), (2) and (3) are defined by their various
substituents. Table 1 illustrates compounds within the scope of the present invention
which are:
of formula (1) wherein Rb, is H, F, Cl, or Br, L is CO, and Rc is H;
of formula (2) wherein Rc is H and L is CO; and
of formula (3) wherein Rc is H, L is CO, and Rc is H.
Examples
The following examples are intended to illustrate but not to limit the invention.
Compound numbers and designations are found in the Illustrative Schemes and in
the prior disclosure.
In these examples, in the first general step of the method, a 6-deoxyerythronolide
B (6-dEB) derivative compound is prepared by fermentation of a recombinant
Streptomyces host cell.
The fermentation to produce 15-methyl-6-deoxyerythronolide B and 14, 15-
dehydro-6-deoxyerythronolide B requires a synthetic diketide intermediate to be fed to
the fermenting cells. The preparation of these synthetic diketides is described in Example
1. These synthetic diketides are substrates for a 6-deoxyerythronolide B synthase (DEBS)
that is unable to act on its natural substrate (propionyl CoA) due to a mutation in the
ketosynthase domain of module 1 of DEBS. This recombinant DEBS is provided by
plasmid pJRJ2 in Streptomyces coelicolor CH999. S. coelicolor CH999 is described in
U.S. Patent No. 5, 672, 491, incorporated herein by reference. A derivative of
S. coelicolor CH999, S. coelicolor K39-02, that has been genetically modified to include
a ptpA gene, is described in U.S. Patent Application Serial No. 09/181, 833, incorporated
herein by reference can also be employed for this purpose.
Plasmid pJPJ2 encodes the eryAI, eryAII, and eryAIII genes; the eryAI gene
contained in the plasmid contains the KS1 null mutation. The KS1 null mutation
prevents formation of the 6-deoxyerythronolide B produced by the wild-type gene unless
oogenous substrate is provided. Plasmid pJRJ2 and a process for using the plasmid to prepare nove113-
substituted erythromycins are described in PCT publication Nos. 99/03986 and 97/02358 and-
in US. patent application Serial Nos. 08/675, 817, filed 5 July 1996; 08/896, 323, filed 17 July
1997; and 09/311, 756, filed 14 May 1999, each of which is incorporated herein by reference.
The exogenous substrates provided can be prepared by the methods and include the
compounds described in PCT patent application No. PCT/US00/02397 and U.S. patent
application Serial No. 09/492, 733, both filed 27 Jan. 2000, by inventors G. Ashley et at., and
both of which claim priority to U.S. patent application Serial No. 60/117, 384, filed 27 Jan.
1999, each of which is incorporated herein by reference. PKS genes other than the ery genes
can also be employed; suitable genes include the KSl null mutation containing oleandolide
and megalomicin PKS genes described in U.S. patent application Serial Nos. 60/158, 305,
filed 8 Oct 1999 and 09/428, 517, filed 28 Oct 1999, and PCT application No; US99/24478,
filed 22 Oct 1999, each of which is incorporated herein by reference.
The fermentation of Streptomyces coelicoIor CH999/pSRJ2 and S, coelicolor
CH999/pCK7 is described in Example 2. The isolation of the 6-deoxyerythronolide products
resulting from this fermentation can be achieved by separation.
The isolated productsare then added to the fermentatiorrbrothof Saccharopolyspora
erythraea strains to make other useful intermediate compounds of the invention. The
S. erythraea strains catalyze the biosynthesis and attachment of sugar residues to the 3 and 5
positions of the 6-dEB derivative compounds. These strains also comprise a functional eryK
gene product and so hydroxylate the 6-dEB derivative compounds at the 12 position. The
strains differ in regard to whether a functional eryF gene product is produced. If so, then the
compounds produced are hydroxylated at the 6 position as well. If not, then a 6-
deoxyerythromycin A derivative is produced. These S. erythraea fermentations are described-
in Example 3, together with the isolation of the erythromycin A derivative compounds from
the fermentation broth.
The isolated products are then used as intermediates in the chemical synthesis of
other intermediate compounds of the invention. For erythromycin A derivative
intermediates that comprise a 6-hydroxyl, Examples 4-6 describe the process for
alkylating the compounds to make the 6-O-alkyl intermediates of the invention. The
schematic for these reactions is shown in Figure 7.
Example 1
Preparation of Diketide Thioesters
The processes used to prepare the N-acetylcysteaminethioesters (NAcS) used to
feed the recombinant Streptomyces host cells to make the 15-methyl and 14, 15-dehydro-
6-deoxyerythronolide B intermediate compounds are described in this Example. The
synthesis protocols described below are also described in PCT Publication No. WO
00/44717 which claims priority to U.S. Pro-visional Patent Application Serial No.
60/117, 384, filed 27 Jan. 1999, incorporated herein by reference.
Thus, (2S, 3R)-2-methyl-3-hydroxyhexanoate NAcS (Preparation E), which is
used to prepare the 15-methyl-6-deoxyerythronolide B intermediate, is prepared from
reacting (4S)-N-[(2S, 3R)-2-methyl-3-hydroxyhexanoyl]-4-benzyl-2-oxazolidinone
(Preparation D) with N-acetylcysteamine (Preparation B). N-acetylcysteamine is, in turn,
prepared from N, S-diacetylcysteamine (Preparation A). (4S)-N-[(2S, 3R)-2-methyl-3-
hydroxyhexanoyl]-4-benzyl-2-oxazolidinonc (Preparation D) is prepared from (4S)-N-
Propionyl-4-benzyl-2-oxazolidinone (Propionyl-Nox; Preparation C).
In similar fashion, (2S, 3R)-2-methyl-3-hydroxy-4-pentenoate NAcS (Preparation
G), which is used to prepare the 14, 15-dehydro-6-deoxyerythronolide B intermediate, is
prepared from reacting (4S)-N-[(2S, 3R)-2-methyl-3-hydroxy-4-pentenoyl]-4-benzyl-2-
oxazolidinone (Preparation F) with N-acetylcysteamine (Preparation B). (4S)-N-
[(2S, 3R)-2-methyl-3-hydroxy-4-pentenoyl]-4-benzyl-2-oxazolidinone (Preparation F) is
prepared from (4S)-N-Propionyl-4-benzyl-2-oxazolidinone (Propionyl-Nox; Preparation
C).
A. N, S-diacetylcysteamine: Cysteamine hydrochloride (50.0 g) is added to a
1 L 3-neck round bottom flask fitted with a magnetic stir bar, 2 addition funnels, and a
pH electrode. Water (300 mL) is added, and the stirred solution is cooled on ice. The pH
is adjusted to 8.0 by addition of 8 N KOH. Acetic anhydride (125 mL) is placed in one
addition funnel, and 8N KOH (350 mL) is placed in the other addition funnel. The acetic
anhydride is added dropwise to the cysteamine solution, with 8 N KOH being added so as
to keep the reaction pH at 8 +/-1. After addition of acetic anhydride is complete, the pH
was adjusted to 7.0 using 1 N HC1 and the mixture is allowed to stir for 75 min. on ice.
Solid NaCl is added to saturation, and the solution is extracted 4 times using 400 mL
portions of CH2Cl2- The organic extracts are combined, dried over MgSO4, filtered, and
concentrated under reduced pressure to yleld 68.9 g (97% yleld) of a pale yellow oil,
which crystallizes upon standing at 4°C.
B. N-acetylcysteamine: N, S-diacetylcysteamine (42.64 g) is placed in a 2 L
round bottom flask fitted with a magnetic stirrer, and dissolved in 1400 mL of water. The
flask is purged with N2, and the mixture is chilled in an ice bath. Potassium hydroxide
(49.42 g) is added, and the mixture is stirred for 2 hr. on ice under inert atmosphere. The
pH is adjusted to 7 using 6 N HC1, and solid NaCl is added to saturation. The mixture is
extracted 7 times with 500 mL portions of CH2Cl2. The organic extracts are combined,
dried over MgSO4, filtered, and concentrated under reduced pressure to yleld 30.2 g (96%
yleld) of product. This material is distilled immediately prior to .use, bp 138-140°C/7
mmHg.
C. (4S)-N-bropionyl-4-berizyl-2-oxazolidinone (Propionyl-NOx): A dry, 1L
three-necked round bottomed flask equipped with a 500 mL addition funnel and a stir bar
was charged with 20 g of (4S)-4-benzyl-2-oxazolidinone, capped with septa and flushed
with nitrogen. Anhydrous THF (300 mL) was added by cannula and the resulting
solution was cooled with a -78°C bath of dry ice/isopropanol. The addition funnel was
charged with 78 mL of n-butyllithium (1.6 M in hexane) by cannula, which was added in
a slow stream to the reaction. Distilled propionyl chloride (bp 77-79°C), 8.0 mL, was
added rapidly via syringe. The reaction was allowed to stir for 30 min. in the dry
ice/isopropanol bath.
The reaction was removed from the cold bath, allowed to warm to >0°C, and
quenched with 50 mL of saturated aqueous NH4CI. The mixture was concentrated to a
slurry on a rotary evaporator. The slurry was extracted three times with 250 mL portions
of ethyl ether. The organic extracts were combined and washed with 50 mL each of
saturated aqueous NaHCO3 and brine, dried with MgSO4, filtered, and concentrated to
give a yellow oil. The material crystallized upon sitting. The crystals were triturated
once with cold (-20°C) hexanes to give 21.0 g (80% yleld) of white crystalline material, m.p. 41-43°C.
APCI-MS: m/z = 234 (MH+), 178, 117. 1H-NMR (360 MHz, CDCl3): ?7.2-7.4
(5H, m); 4.67 (lH, m, H4); 4.14-4.22 (2H, m, H5); 3.30 (lH, dd, J=3, 13 Hz, benzylic); 2.89-
3.03 (2H, m, H2'); 2.77 (lH, dd, J=9, 13, benzylic); 1.20 (3H, t, J=7 Hz, H2).
D. (4S)-N-[(2S, 3R)-2-methyl-3-hydroxyhexanoyl]-4-benzyl-2-oxazolidinone:
A dry, 2 L three-necked round bottomed flask equipped with a 500 mL addition funnel, a
low-temperature thermometer, and a stir bar was charged with 19.84 g of N-propionyl-
oxazolidinone, capped with septa and flushed with nitrogen. Anhydrous dichloromethane
(100 mL) was added by cannula, and the resulting solution was cooled to -65°C in a bath
of dry ice/isopropanol. The addition funnel was charged by cannula with 100 mL of
dibutylboron triflate (1.0 M in dichloromethane), which was added in a slow stream to the
reaction. Triethylarmine (15.6 mL) was added dropwise by syringe, keeping the reaction
temperature below -10°C. The reaction was then transferred to an ice bath and allowed to
stir at 0°C for 30 min. After that period, the reaction was placed back into the dry
ice/isopropanol bath and allowed to cool to -65°C. Butyraldehyde (8.6 mL) was added
rapidly by syringe, and the reaction was allowed to stir for 30 min.
The reaction was transferred to an ice bath and the addition funnel was charged
with 100 mL of a 1 M aqueous phosphate solution, pH 7.0 (the phosphate solution is
comprised of equal molar amounts of mono- and dibasic potassium phosphate). The
phosphate solution was added as quickly as possible while keeping the reaction
temperature below 10CC. The addition funnel was then charged with 300 mL methanol
which was added as quickly as possible while keeping the reaction temperature below
10°C. Finally, the addition funnel was charged with 300 rnL of 2:1 methanol:30%
hydrogen peroxide. This was added dropwise to ensure that the temperature was kept
below 10°C. The reaction was stirred for one hr. after completion of addition. The
solvent was then removed on a rotary evaporator until a slurry remained. The slurry was
extracted 4 times with 500 mL portions of ethyl ether. The combined organic extracts
were washed with 250 mL each of saturated aqueous sodium bicarbonate and brine. The
extract was then dried with MgSO4, filtered, and. concentrated to give a slightly yellow
oil. The material was then chromatographed on SiO2 using 2:1 hexanes:ethyl acetate
(product Rf = 0.4) resulting in 22.0 g (85% yleld) of title compound as a colorless oil.
APCI-MS: m/z 306 (MH+); 1H-NMR (360 MHz, CDC13): ?7.2-7.4 (5H.m,
phenyl); 4.71 (1H, m, H4); 4.17-4.25 (2H, m, H5); 3.96 (lH, m, H3;); 3.77 (lH, dq, J=2.5, 7
Hz, H2', ); 3.26 (1H, dd, J=4, 13 Hz, benzylic); 2.79 (1H, dd, J=9, 13 Hz, benzylic); 1.5-1.6
(2H, m, H4'); 1.3-1.5 (2H, m, H5'); 1.27 (3H, d, J=7 Hz, 2:-Me); 0.94 (3H, t, J=7 Hz, H6').
E. (2S, 3R)-2-methyl-3-hydroxyhexanoate N-acetylcysteamine thioester: N-
acetylcysteamine was distilled at 130°C/7 mm Hg to give a colorless liquid at room
temperature. A dry, 1 L three-necked round bottomed flask equipped with a 500 mL
addition funnel and a stir bar was capped with septa and flushed with nitrogen. The flask
was then charged with 10.7 mL of N-acetylcysteamine by syringe and with 400 mL of
anhydrous THf by cannula. The mixture was cooled with a MeOH/ice bath.
Butyllithium (64 mL of 1.6 M in hexanes) was added dropwise by syringe, resulting in
formation of a white precipitate. After stirring for 30 min., trimethylaluminum (51 mL of
2.0 M in hexanes) was added dropwise by syringe. The reaction became clear after
addition of trimethylaluminum and was allowed to stir an additional 30 min. During this
period, 20.5 g (0.068 mol) of (4S)-N-[(2S, 3R)-2-methyl-3-hydroxylhexanoyl]-4-benzyl-2-
oxazolidinone was put under a blanket of nitrogen and dissolved in 100 mL of anhydrous
THF; this solution was then transferred in a slow stream by cannula into the reaction.
The resulting reaction mixture turned a yellow-green color and was allowed to stir for 1
hr. The reaction was finished when the starting material could no longer be seen by thin-
layer chromatographic analysis (ca. 1 hr.)-
The reaction was treated with enough saturated oxalic acid to give a neutral
reaction with pH paper (approximately 90 niL). The solvents were then removed on a
rotary evaporator to give a white slurry. The slurry was extracted six times with 250 mL
portions of ethyl ether. The organic extracts were combined and washed with brine, dried
with MgSO4, filtered, and concentrated to give a slightly yellow oil. The thioester
product was purified by flash chromatography on SiO2 using 1:1 hexanes:EtOAc until the
elulion of 4-benzyl-2-oxazolidinone. At that point, the solvent system was switched to
100% EtOAc to give pure fractions of diketide thioester. The product fractions were
combined and concentrated to give 14.9 g (89% yleld) of title compound. This
compound is referred to as the propyl diketide thioester in Example 2.
APCI-MS: m/z 248 (MH+); 1H-NMR (360 MHz, CDC13): ?5.8 (br s, lH); 3.94 (dt, lH), 3.46 (m, 2H), 3.03 (dt, 2H)3 2.71 (dq, lH), 1-97 (s, 3H), 1.50 (m, 2H), 1.37 (m, 2H),
1.21 (d, 3H), 0.94 (t, 3H).
F. (4S)-N-[(2S.3R)-2-methyl-3-hydroxy-4-pentenoyll-4-benzyl-2-
oxazolidinone: A dry, 2 L three-necked round bottomed flask equipped with a 500 mL
addition funnel, a low-temperature thermometer, and a stir bar was charged with 20.0 g of
propionyl oxazolidinone A, capped with septa and flushed with nitrogen. Anhydrous
dichloromethane (100 ml) was added and the resulting solution was cooled to -15°C in a
bath of methanol/ice. Dibutylboron trifiate (100 mL of 1.0 M in dichloromethane) was
added in a slow stream via the addition funnel at such a rate as to keep the reaction
temperature below 3°C. Diisopropylethylamine (17.9 mL) was added dropwise by
syringe, again keeping the internal temperature below 3°C. The reaction was then cooled
to -65°C using a dry ice/isopropanol bath. Acrolein was added over 5 min. by syringe.
The reaction was allowed to stir for 30 min. after completion of addition.
The reaction was then transferred to an ice bath and the addition funnel was
charged with 120 mL (0.1 mol) of a 1 M aqueous phosphate solution, pH 7.0 (the
phosphate solution is comprised of equal molar amounts of mono- and dibasic
phosphate). The phosphate solution was added as quickly as possible while keeping the
reaction temperature below 10°C. The addition funnel was then charged with 400 mL of
methanol that were added as quickly as possible while keeping the reaction temperature
below 10°C. Finally, the addition funnel was charged with 400 mL of 2:1 methanol:30%
hydrogen peroxide by initial dropwise addition to keep the temperature below 10°C. The
reaction was stirred for one hour. The solvent was removed using a rotary evaporator,
leaving a slurry. The slurry was extracted 4 times with 500 mL portions of ethyl ether.
The organic extracts were combined and washed with 250 mL each of saturated sodium
bicarbonate and brine, then dried with MgSO4, filtered, and concentrated to give a slightly
yellow oil. Trituration with hexane induced crystallization. Recrystallization from ether
by addition of hexane resulted in 13.67 g (55% yleld) of product.
1H-NMR (360 MHz, CDC13): ?7.2-7.4 (m, 5H); 5.86 (ddd, lH), 5.35 (dt, lH), 5.22
(dt, IH), 4.71 (m, lH), 4.51 (m, lH), 4.21 (m, 2H), 3.89 (dq, lH), 3.26 (dd, lH), 2.80
(dd, lH), 1.25 (d, 3H).
G. (2S.3R)-2-methyl-3-hydroxy-4-pentenoate N-acetylcysteamine thioester:
N-acetylcysteamine was distilled at 130°C/7 mm Hg to give a colorless liquid at room
temperature. A dry, 1 L three-necked round bottomed flask equipped with a 500 mL
addition funnel and a stir bar was capped with septa and flushed with nitrogen. The flask
was then charged with 7.5 mL of N-acetylcysteamine by syringe and with 500 mL of
anhydrous THF by cannula. The reaction was then cooled with a MeOH/ice bath.
Butyllithium (44 mL of 1.6 M in hexane) was added dropwise by syringe. A white
precipitate formed as the n-BuLi was added. After stirring for 30 min., 35.5 mL (0.071
mol) of trimethylaluminum (2.0 M in hexane) were added drop-wise by syringe. The
reaction became clear after addition of trimethylalurninum and was allowed to stir an
additional 30 min. (4S)-N-[(2S, 3R)-2-methyl-3-hydroxy-4-pentenoyl]-4-benzyl-2-
oxazolidinone from Preparation F (13.6 g) was put under a blanket of nitrogen, dissolved
in 50 mL of anhydrous THF, and this solution was then transferred in a slow stream by
cannula into the reaction. The resulting reaction mixture turned a yellow-green color and
was allowed to stir for 1 hr. The reaction was judged to be finished when starting
material could no longer be seen by thin-layer chromatography (ca. 30 min.).
Enough saturated oxalic acid was added to give a neutral reaction with pH paper
(approximately 60 mL). The solvents' were then removed by rotary evaporator to give a
white slurry. The slurry was extracted six times with 250 mL portions of ethyl ether. The
organic extracts were combined, washed with brine, dried with MgSO4, filtered, and
concentrated to give a slightly yellow oil. The thioester was then purified by flash
chromatography on SiO2. The column was run with 1:1 hexanes: ethyl acetate until the
elution of oxazolidinone. At that point, the eluent was switched to 100% ethyl acetate to
give pure fractions of product. The fractions were combined and concentrated to give 7.7
g (71% yleld) of title compound product. This product is referred to as the vinyl diketide
thioester in Example 2.
1H-NMR (360 MHz, CDC13): ?5.82 (ddd.1H), 5.78 (br s, 1H), 5.32 (dt, 1H), 5.21
(dt, 1H), 4.47 (m, lH), 3.45 (m, 2H), 3.04 (m, 2H), 2.81 (dq, lH), 1.96 (s, 3H), 1.22 (d, 3H).
Example 2
Preparation of Erythronolide
A. 15-methyl-6-deoxyerythronolide B (Compound P, Rd=propyl):
Streptomyces coelicolor CH999/pJPJ2 is described in PCT Publication No. WO
97/02358 which claims priority to U.S. Patent Application Serial Nos. 08/896, 323, filed
17 July 1997, and 08/675, 817, filed 5 July 1996, each of which is incorporated herein by
reference. Plasmid pJRJ2 encodes a mutated form of DEBS in which the ketosynthase
domain of module 1 (KS1) has been inactivated via mutagenesis (KS1°). S. coelicolor
strains comprising this plasmid that are fed (2S, 3R)-2-methyl-3-hydroxyhexanoate-N-
acetylcystermina (Preparation E, propyl diketide) of Example 1 produce 15-methyl-6-
deoxyerythronolide B.
A 1 mL vial of the CH999/pJRJ2 working cell bank is thawed and the contents of
the vial are added to 50 mL of Inoculum Medium 1 in a 250 mL baffled flask. The flask
is placed in an incubator/shaker maintained at 30±1°C and 175±25 RPM for 48±10 hours.
The 50 mL culture is then added to a 2.8 L baffled flask containing 500 mL of Inoculum
Medium 1. This flask is incubated in an incubator/shaker at 30±1°C and 175±25 RPM
for 48±10 hours. The 500 mL culture is divided equally among ten 2.8 L baffled flasks
each containing 500 mL of Inoculum Medium 1. All flasks are then incubated as
described previously.
A 150 L fermenter is prepared by sterilizing 100 L of Production Medium 1 at
121°C for 45 minutes. After incubation, al110 flasks are combined in a 5 L sterile
inoculation bottle and aseptically added to a 150 L fermenter. The fermenter is controlled
at 30°C, pH 6.5 by addition of 2.5 N H2SO4 and 2.5 NNaOH, dissolved oxygen = 80%
air saturation by agitation rate (500-700 RPM), air flow rate (10-50 LPM), and/or back
pressure control (0.1-0.4 bar). Foam is controlled by the intermittent addition of a 50%
solution of Antifoam B.
At 24±5 hours (2S, 3R)-2-methyl-3-hydroxyhexanoyl-N-acetylcysteamine (propyl
diketide, Preparation E in Example 1) is added to a final concentration of 1 g/L. Propyl
diketide is prepared by solubilizing in dimethyl sulfoxide at a ratio of 1:4 (diketide to
DMSO) and then filter sterilized (0.2 µm, nylon filter). Production of 15-methyl-6-
deoxyerythonolide B (15-methyl-6dEB) ceases on day 7 and the fermenter is harvested.
The fermentation broth is centrifuged at 20, 500 g in an Alpha Laval™ AS-26 centrifuge.
The product is predominantly in the centrate; the centrifuged cell mass is discarded.
This process has also been completed in a 1000 L fermenter (700 L working
volume). The inoculum process is identical to the above process except that the 150 L
fermenter is charged with Inoculum Medium 1 and the 1000 L fermenter is charged with
Production Medium 1. The fermenter is controlled at 30°C, pH 6.5 by addition of 2.5-5 N
H2SO4 and 2.5-5 N NaOH, dissolved oxygen =70% air saturation by agitation rate (140-
205 RPM), air flow rate (100-200 LPM), and/or back pressure control (0.2-0.5 bar).
Foam is controlled by the addition of a 50% solution of Antifoam B as needed. At 24±5
hours racemic 2-methyl-3-hydroxyhexanoyl-N-propionylcysteamine (300 grams) is added
to the 1000 L fermenter. The fermenter is harvested at 4.6 days by centrifugation as
described above.
Media used in this process include the following:
Sterilized by autoclaving for 60 minutes at 121 °C.
Post-sterile additions:
1) 1 mL/L of 50 mg/ml Thiostrepton in 100% DMS O, sterile filtered.
2) 1 mL/1100% Antifoam B silicon emulsion (J.T. Baker), autoclaved.
3) 40 mL of 500 g/L glucose, sterile filtered.
Sterilized in fermenter for 45 minutes at 121°C.
Post-sterile additions for Production Medium 1 :
1) 1 mL/L of 50 mg/ml Thiostrepton in 100% DMSO, sterile filtered.
2) 1 mL/L of 100% Antifoam B (J.T. Baker), autoclaved.
After centrifugation, the centrate is filtered. The filtrate (approximately 700 L)
are passed through an Amicon™ Moduline column (20 x 350 cm) containing 20 L of
HP20 resin (Mitsubishi). The flow rate during loading is 4 L/minute with a pressure drop
below 8 psi (55, 152 Pa). After loading the resin is washed with 20 L of water and then 40
L of 30% methanol. 15-methyl-6dEB is eluted using 100% methanol. Four 12 L fractions
were collected with fractions 2, 3 and 4 containing all of the detectable 15-methyl-6dEB.
The l5-methyl-6dEB product pool is diluted with 36.7 L of water giving 75 L of a clear
solution. This solution is loaded directly onto a 5 L Amicon™ Vantage Column
containing HP20SS resin (Mitsubishi). Column loading is carried out at 1 IVminute. The
column is eluted with 20 L of 65% methanol, 20 L of 70% methanol, 20 L of 80%
methanol, and finally 20 L of 100% methanol. A total of 16 x 5 L fractions were
collected. The 80% fractions along with the last 70% fraction were combined (25 L) and
evaporated to dryness. The resulting residue is dissolved in 1 L of 100% methanol,
filtered, evaporated, and dried in a vacuum oven at 40°C. This process resulted in 33 g of
a solid product containing 93% 15-methyl-6dEB.
B. 14.15-dehydro-6-deoxyerythronoride B (Compound P, Rd=vinyl):
S, coelicolor strains comprising this plasmid that are fed (2S, 3R)-2-methyl-3-
hydroxy-4-pentenoate NAc Cysteamine thioester (Preparation G) of Example 1 produce
14, l5-dehydro-6-deoxyerythronolide B when prepared in accordance with the process
described in Preparation A above to produce 15-methyl-6-deoxyerythronolide B.
C. 14-nor-6-deoxyerythronolide B (Compound P, Rd=methyl): Similarly, 14-
nor-6-deoxyerythronolide B is produced using S. coelicolor CH999/pCK7 host, when
prepared in accordance with the process described in Example 2A
Example 3
Preparation of Erythromycins
The 6-dEB derivative compounds produced in Example 2, Preparations A-C are
converted to erythromycin derivatives using a recombinant strain of Saccharopolyspora
erythraea. For production of erythromycins having both the 6- and 12-hydroxyl groups,
the S. erythraea strain used was K40-67 or K39-14V. This strain was created by
transforming an S. erythraea strain capable of producing high levels of erythromycin A
with a pWHM3-derived plasmid comprising a mutated eryAl sequence encoding an
inactivated KS1 domain. By homologous recombination, the resulting transformants
were rendered incapable of producing 6-deoxyerythronolide B. Thus the dEB analog fed
is not subject to competition for hydroxylation at the 6-posirion. For production of
erythromycin derivatives having only the 12-hydroxyl group, the S. erythraea strain used
was K39-07. This strain was constructed from strain K40-67 by disruption of the eryF
hydroxylase gene; this destroys ability to hydroxylate the analog at the 6-position. Both
strains were fermented under substantially similar conditions, as described below.
15-methyl-erythromycin A: 15-methyl-erythromycin A is produced according to
the following protocol: A 1 mL vial of the K39-14V working cell bank is thawed and the
contents of the vial are added to 50 mL of Inoculum Medium 2 in a 250 mL baffled flask.
The flask is placed in an incubator/shaker maintained at 34±1°C and 175+25 RPM for
4S±10 hours. The 50 mL culture is then added to a 2.8 L baffled flask containing 500 mL
of Inoculum Medium 2. The flask is incubated in an incubator/shaker at 34±1°C and
175±25 RPM for 48±10 hours. The 500 mL culture is divided equally among ten 2.8 L
baffled flasks each containing 500 mL of Inoculum Medium 2. All flasks are then
incubated as described previously.
A 150 L fermenter is prepared by sterilizing 100 L of Production Medium 2 at
121°C for 45 minutes. After incubation, al110 flasks are combined in a 5 L sterile
inoculation bottle and aseptically added to a 150 L fermenter. The fermenter is controlled
at 34°C, pH 7.0 by addition of 2.5 N H2SO4 and 2.5 N NaOH, dissolved oxygen 2 80%
air saturation by agitation rate (500-700 RPM), air flow rate (15-50 LPM), and/or back
pressure control (0.1-0.4 bar). Foam is controlled by the addition of a 50% solution of
Antifoam B.
At 24±5 hours a 58-60 mL/hour 15% dextrin (w/v) feed is initiated. The dextrin
solution is continuously mixed during the feed period. At 24±5 hours 25 grams of 15-
methyl-6dEB (Preparation A in Example 2) are added to the fennenter. The 15-methyl-
6dEB is prepared by solubilizing 25 grams of 15-methyl-6dEB in 400-600 mL of 100%
ethanol and filtering (0.2 µm, nylon filter). Conversion of 15-methyl-6dEB to 15-methyl-
erythromycin A ceases after 60±10 hours and the fermenter is harvested. The
fermentation broth is centrifuged at 20, 500 g in an Alpha Laval™ AS-26 centrifuge. The
product is predominantly in the centrate; the centrifuged cell mass is discarded.
Media used in this process include the following:
Inoculum Medium 2
Sterilized by autoclaving for 60 minutes at 121°C.
Post-sterile addition:
1 mL/1100% Antifoam B (J.T. Baker), autoclaved.
Production Medium 2
Sterilized in fermenter for 45 minutes at 121 °C.
Centrifuged fermentation broth (127 L) containing 34 g of the target molecule is
passed through 18.3 L of HP20 sorbent packed into an Amicon™ P350 Moduline 2
chromatography column. At 4 L/min loading, backpressure is found to be less than 5 psi
(34, 470 Pa). Following loading, the resin is washed with 20 L deionized water and then
40 L of 30% methanol. 15-Methyl-Erythromycin A is eluted using 54 L of 100%
methanol. The product pool is evaporated using a Buchi™ rotary evaporator (R-152). The
solids were dissolved in a minimal amount of 100% methanol, filtered and the filtrate
evaporated to dryness. This resulted in 123 g of material containing 30% 15-Methyl-
Erythromycin A by weight. 80 grams of the 30% material is extracted twice with 1 L of
40°C acetone. The acetone extract is filtered, and the filtrate is dried on the inside surface
of a 20 L rotary evaporation flask. The solids were extracted with 9:1 hexane to acetone
three times at 40°C. The organic extracts were pooled and evaporated to dryness giving
32 g of solids enriched (68%) in 15-Methyl-Erythromycin A. The product pool from the
acetone/hexane extraction is dissolved in 1 L of methanol to which an equal amount of
water is added. The methanol solution is loaded onto a HP20SS chromatography column
(Kontes) previously washed and equilibrated with 50% methanol. Column dimensions
were 4.8 x 115 cm. Column loading with respect to 15-Methyl-Erythromycin A is 11 g/L.
The column is washed with 50% (0.8 L) and 60% (8 L) methanol in water. Elution of the
target molecule is carried out using 70% (8L), 80% (16 L) and 85% (8 L) methanol in
water. 1 L fractions were collected. Fractions 11-29 were combined, evaporated and dried
in a vacuum oven giving 23 g of product with 93% purity.
This material served as starting material for the chemical derivatization
procedures described in the following examples. The following compounds are also
produced by this methodology: (i) 14-norerythromycin A (Rd=Me); (ii) 14, 15-dehydro-
erythromycin A (Rd=allyl); (iii) 14-nor-6-deoxy-erythrcmycin A; (iv) 14, 15-dehydro-6-
deoxy-erythromycin A; and (v) 15-methyl-6-deoxy-erythromycin A. When used to make
3-descladinose-3-oxo-derivatives, the erythromycin A derivatives were not separated
from the erythromycin C derivatives; instead, mixtures of the erythromycin A and
erythromycin C compounds were used as starting materials for chemical derivatization.
These products were extracted and purified as follows:
In general, fermentation broths are brought to pH 8.0 by addition of NaOH and
ethanol is added (0.1 L/L broth). The broth is clarified by centrifugation and loaded onto
an XAD-16 resin (Rohm and Haas) column (1 kg XAD/1 g erythromycin analogs) at a
flow rate of 2-4 mL/cm2-min. The loaded resin is washed with 2 column volumes of 20%
(v/v) ethanol in water and the erythromycin analogs are eluted from the resin with acetone
and collected in 1/2 column volume fractions. The fractions containing erythromycin
analogs are identified by thin-layer chromatography (ethyl acetate:hexanes 1:1) and
HPLC/MS.
The acetone fractions containing erythromycin analogs are pooled and the
volatiles are removed under reduced pressure. The resulting aqueous mixture is extracted
with ethyl acetate. The ethyl acetate extract is washed with saturated NaHCO3 and brine
solutions, dried over sodium or magnesium sulfate, filtered, and concentrated to dryness
under reduced pressure. Crude material is dissolved in dichloromethane and loaded onto
a pad of silica gel and washed with dichloromethane:methanol (96:4 v/v) until the eluent
is no longer yellow. The desired material is with
dichloromethane: methanol:triethylamine (94:4:2 v/v) and collected in fractions.
Fractions containing erythromycin are identified by thin-layer chromatography, collected
and concentrated under reduced pressure. This material is recrystallized from
dichloromethane/hexanes.
This general procedure is illustrated as follows:
(i) 14-norerythromycins: 1 liter of ethanol was added to each of 10 liters of
fermentation broth. The broth was centrifuged and the supernatant was passed through

0.6 Uters of XAD (column-dimensions 17 cm x 6.5) cm at a flow rate of 100 mL/min.
After loading, the column was washed with 1.5 liters of 20% (v/v) ethanol in water. The
desired material was then eluted with acetone. The fractions containing this material were
concentrated under reduced pressure until the volatiles were removed and the aqueous
remainder was extracted with ethyl acetate. The ethyl acetate layers were washed with
saturated sodium bicarbonate solution, brine, dried with magnesium sulfate and
concentrated under reduced pressure to give the crude extract.
Crude material (0.6 g) was dissolved, in dichloromethane and gravity filtered
through a 3 cm pad of silica gel in a 6 cm diameter fritted funnel. The material was
eluted with 400 mL of dichloromethane followed by 400 mL
dichloromethane:methanol:triethylamine (90:10:2 v/v) and collected in 40 mL fractions.
Fractions containing erythromycin were identified by thin-layer chromatography
(ether:methanol:NH4OH 90:8:2 v/v, Rf- 0.35 and dichloromethane:methanol 95:5 v/v,
Rf - 0) and concentrated under reduced pressure. This material was recrystallized from
dichloromethane/hexanes.
(ii) 15-methyl-erythromycin A: 8 liters of ethanol was added to approximately
80 liters of fermentation broth. The broth was centrifuged and the supernatant was passed
through 2.5 liters of XAD at a flow rate of 230 mL/min. After loading the column was
washed with 1 liter of water and 5 liters of 20% (v/v) ethanol in water. The desired
material was then eluted with acetone. The fractions containing this material were
concentrated under reduced pressure until the volatiles were removed and the aqueous
remainder was extracted with ethyl acetate. The ethyl acetate layers were washed with
saturated sodium bicarbonate solution, brine, dried with magnesium sulfate and
concentrated under reduced pressure to give the crude extract
Crude material (8.3 g) was dissolved in dichloromethane and gravity filtered
through a 3 cm pad of silica gel in a 9 cm diameter fritted funnel. The material was
eluted with 200 mL of dichloromethane followed by 600 mL of dichloromethane:
methanol (96:4 v/v) followed by 900 mL dichloromethane:methanol:triethylamine
(89:9:2 v/v) and collected in 40 mL fractions. Fractions containing erythromycin were
identified by thin-layer chromatography (ether.methanol:NH4OH 90:8:2 v/v, Rf ~ 0.4 and
dichloromethane:methanol 95:5, Rr~ 0.05) and concentrated under reduced pressure.
This material was re-subjected to the above procedure before it was suitable for
recrystallization.
(iii) 14-nor-6-deoxy-erythromycins: 1 liter of ethanol was added to each of
two 10 liter fermentations. The broths were centrifuged and the supematants were
combined for a total of approximately 22 liters. The combined broths were then passed
through 1 liter of XAD (column dimensions 23.5 cm x 6.5 cm (i.d.) at a flow rate of 170
mL/min. After loading the column was washed with 2 liters of 20% (v/v) ethanol in
water. The desired material was then elutcd with acetone. The fractions containing this
material were concentrated under reduced pressure until the volatiles were removed and
the aqueous remainder was extracted with ethyl acetate. The ethyl acetate layers were
washed with saturated sodium bicarbonate solution, brine, dried with magnesium sulfate
and concentrated under reduced pressure to give the crude extract.
(iv) 15-methyl-6-deoxy-erythromycins: 1 liter of ethanol was added to each of
3 fermentors containing 10 liters of broth. The broths were centifuged and the
supernatant was passed over 1.25 liters of XAD (column dimensions 40 cm x 6.5 cm) at a
flow rate of 130 mL/min. The column was then washed with 3 liters of 20% (v/v) ethanol
in water. The desired material was then eluted with acetone. The fractions containing this
material were concentrated under reduced pressure until the volatiles were removed and
the aqueous remainder was extracted with ethyl acetate. The ethyl acetate layers were
washed with saturated sodium bicarbonate solution, brine, dried with magnesium sulfate
and concentrated under reduced pressure to give the crude extract
Crude material (2.8 g) was dissolved in dichloromethane and gravity filtered
through a 3 cm pad of silica gel in a 6 cm diameter fritted funnel. The material was
eluted with 400 mL of dichloromethane:methanol (96:4 v/v) followed by 400 mL
dichloromethane:methanol-.triethylamine (89:9:2 v/v) and collected in 40 mL fractions.

Fractions containing erythromycin were identified by thin-layer chromatography
(ether:methanol:NH4OH 90:8:2 v/v and:dichloromethane:methanol 95:5) and
concentrated under reduced pressure. This material required further purification by silica
gel chromatography.
Example 4
Synthesis of 6-O- methyl-14-norerythromycin A, i.e.. Formula (4)
where Ra=Me, Rd.=Me, Rc=H. Rc=H
A. 14-Norerythromycin A 9-Oxime: A solution of 14-norerythromycin A
(0.621 g, 80% pure), hydroxylamine (0.5 ml of 50% aqueous solution) and acetic acid
(0.2 ml) in isopropanol (2 ml) was kept at 50°C for 22 hours. It was extracted with
chloroform/ethanol (3/2), washed with sodium bicarbonate, brine, and dried over MgSO4.
Filtration and evaporation in vacuo ylelded a crude product (0.65 g) as a white solid
which was used directly for next transformation.
B. 14-Norerythromycin A-9-[O-( 1 -isopropoxycyclohexyl)]oxime: To a
solution of above crude 14-noreythromycin A 9-oxime (0.65 g) and 1, 1-diisopropoxy-
cyclohexanone (0.95 ml) in methylene chloride (2 ml) was added pyridinium P-
toluenesulfonate (PPTS) (0.333 g) in methylene chloride (2 ml). After stirring overnight,
the mixture was extracted (chloroform/ethanol 3:2), washed (NaHCO3-H2O, brine), and
dried (MgSO4). After filtration and evaporation in vacuo, the crude product was
repeatedly driven with toluene and isopropanol to yleld 0.74 g of product, which was used
directly for next reaction.
C. 2', 4"-bis-O- trimethylsilyl-l 4-norerythromycin A-9-[O-( 1 -
isopropoxycyclohexyl)]oxime: To a solution of 14-norerythromycin A 9-[O-(l-
isopropoxycyclohexyl)]oxime (0.74 g) in methylene chloride (6 ml) was added a solution
of trimethylsilyl imidazole (0.33 ml) and trirnethylsilyl chloride (0.18 ml) in methylene
chloride (2 ml) at 0°C. After 5 minute stirring, ethyl acetate was added, washed
(NaHCO3-H2O, brine), and dried (MgSO4). Flash chromatography on silica gel (10:1
hexanes:acetone, 1% triethylamine) afforded pure product as a white solid (0.50 g). Mass
spectrometry reveals [M+H]+= 1020.
D. 6-O- methyl-2', 4"-bis-O- trimethylsilyl-14-Norerythromycin A- 9-[O-(1-
isopropoxycyclohexyl)]oxime: A solution of 2', 4"-bis-O- trimethylsilyl-14-
norerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime (0.3 g, 0.29 mmol) in 1:1
methylsuylfoxide/tetrahydrofuran (DMSO/THF) (1.4 ml) was treated with 0.3 ml of a 2
M solution of methyl bromide in ether and cooled to 10°C. A mixture of 1 M solution of
potassium tert-butoxide in THF (0.6 ml) and DMSO (0.6 ml) was added over 6 hours
using a syringe pump. The reaction was then diluted with ethyl acetate, washed with
saturated NaHCO3, brine, and dried over MgSO4. Filtration and evaporation in vacuo
ylelded a crude product (0.29 g) as a white solid. Mass spectrometry reveals [M+H]+ =
1034.
E. 6-O- methyl-14-Norerythromycin A 9-oxime: Amixture of 6-O- methyl-
2', 4"-bis-trimethylsilyl-14-norerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime
(0.29 g), acetic acid (3.6 ml), acetonitrile (6 ml) and water (3 ml) was stirred at ambient
temperature for 4.5 hours. The mixture was driven to dryness using toluene to give a
crude product as white solid (0.24 g), which was used directly for next step without
further purification.
F. 6-O- methyl-14-norerythromycin A: A mixture of 6-O- methyl-14-
norerythromycin A 9-oxime (0.24 g), sodium hydrosulfite (0.45 g, 85% pure), water (3
ml), ethanol (3 ml) and formic acid (0.07 ml) was kept at 85°C for 8 hours. The reaction
was brought to pH 8 with 1 N NaOH and extracted with ethyl acetate. The organic
extract was washed with brine, dried over MgSO4, filtered, and concentrated to yleld a
crude product as a white solid (0.2 g). Mass spectrometry reveals [M+H]+ = 735.
Example 5
Synthesis of 6-O- methyl-14, 15-dehydroerythromycin A, i.e.. Formula (4) where
Rd=-CH=CH2, Ra=Me Rc=H. Rc=H
A. 14.15-dehydroerythromycin A 9-oxime
A suspension of 14, 15-dehydroerythromycin A (1.984 g, 47% purity, 1.2 mmol)
in 6 mL of 2-propanol was treated with 1.97 mL of 50% aqueous hydroxylamine and
stirred until dissolved. Acetic acid (0.62 mL) was added and the mixture was stirred for
25 hours at 50°C Upon cooling to ambient temperature, saturated NaHCO3 was added
and the mixture was concentrated en vacuo to remove isopropanol. The resulting
aqueous mixture was extracted three times with 250-mL portions of CHCl3. The organic
extracts were combined, washed with saturated NaHCO3, water, and brine, then dried
over MgSO4, filtered, and concentrated to yleld 0.92 g of product.
B. 14.15-dehydroerythromycin A 9-[O-(1-isopropoxycyclohexyl)]oxime
The oxime from (A) (0.92 g) was dissolved in 6.2 mL of CH2Cl2 and treated with
1, 1-diisopropoxycyclohexane (1.23 g) and pyridinium p-toluenesulfonate (0.464 gm) for
15 hours at ambient temperature. The mixture was diluted with 160 mL of CH2Cl2, then
washed sequentially with saturated NaHCO3, water, and brine. The organic phase was
dried with MgSO4, filtered, and evaporated to yleld a brown syrup. Chromatography on
silica gel (grathent from toluene to 1:1 toluene/acetone +1% Et3N) ylelded 0.998 g of
product.
C. 2', 4"-bis(O-trimethylsilyl)- 14.15-dehydroerythromycin A 9-[O-(1-
isopropoxycyclohexyl)]oxime
A solution of 14, 15-dehydroerythromycin A 9-[O-(l-
isopropoxycyclohexyl)]oxime (998 mg, 9.96) in 1.1.25 mL of CH2C12 was cooled on ice
under inert atmosphere and treated with a solution of chlorotrimethylsilane (0.24 mL) and
1-trimethylsilylimidazole (0.44 mL). After 30 minutes, the reaction was diluted with 250
mL of ethyl acetate and washed sequentially with saturated NaHCO3, water, and brine.
The organic phase was dried with MgSO4, filtered, and evaporated to yleld 1.002 g of
product.
D. 2', 4"-bis(O-trimethyl)-6-O-methyl-14, 15-dehydroerythromycin A 9:
[O-( I -isopropoxycyclohexyl)]oxime
A solution of 2', 4"-bis-O- trimethylsilyl-14, 15-dehydroerythromycin A 9-[O-(1-
isopropoxycyclohexyl)]oxime (1.00 g, 20.7 mmol) in 9.69 mL of 1:1
tetrahydrofuran/methylsulfoxide was cooled to 10°C and treated with 0.97 mL of 2.0 M
methyl bromide in ether under inert atmosphere. A mixture of methylsulfoxide (1.94 mL)
and 1.0 M potassium rert-butoxide in tetrahydrofuran (1.94 mL) was added slowly. The
reaction was monitored by thin-layer chromatography (silica gel, 10:1 toluene/acetone),
and was judged complete after addition of 1.6 molar equivalents of base. The reaction
was diluted with 200 mL of ethyl acetate and 70 mL of saturated NaHCO3. The mixture
was transferred to a separatory funnel, diluted with 850 mL of ethyl acetate and 280 mL
of saturated NaHCO3, then washed sequentially with water and brine. The organic phase
was dried with MgSO4, filtered through Celite™, and evaporated to yleld 21.2 g of crude
6-O- methyl-2', 4"-bis-O- trimethylsilyl-l4, 15-dehydroerythromycin A 9-[O-(l-
isopropoxycyclohexyl)]oxime. This was carried on without further purification.
E. 6-O- methyl-14.15-dehydrocrythromycin A 9-oxime
A solution of 6-O-methyl-2', 4"-bis-O- trimethylsilyl-14, 15-dehydroerythromycin
A 9-[O-(l-isopropoxycyclohexyl)]oxime (1.0 g) in 9.8 mL of 2:1 acetonitrile/water was
treated with 5.3 mL of acetic acid, and stirred for 8 hours at ambient temperature. The
mixture was concentrated en vacuo, then repeatedly concentrated after addition of toluene
to yleld 0.797 g of crude 6-O- methyl-14, 15-dehydroerythromycm A 9-oxime.
F. 6-Q-methyl-14.15-dehydroerythromycin A
A solution of 6-O- methyl-14, 15-dehydroerythromycin A 9-oxime (0.797 g) and
sodium hydrosulfite (85%, 1.02 g) in 7.5 mL of 1:1 ethanol/water was placed under inert
atmosphere. Formic acid (0.186 mL) was added dropwise, and the mixture was stirred at
80°C for 3 hours. After cooling to ambient temperature, the reaction was adjusted to pH
10 with 6 N NaOH and extracted three times with 150-mL portions of ethyl acetate. The
organic extracts were combined and washed sequentially with saturated NaHCO3, water,
and brine. The organic phase was dried with MgSO4, filtered, and evaporated to yleld
0.68 g of 6-O- methyl-14, 15-dehydroerythromycin A suitable for further conversion.
Example 6
Synthesis of 6-O-methyl-l 5-methylerythromycin A, i.e.. Formula (4) where Rd=propyl
Ra=Me. Rc=H. Rc=H
A_ 15-Methylerythromycin A 9-Oxime: A suspension of 15-
methylerythromycin A (20.0 g, 85% purity, 22.6 mmol) in 40 mL of 2-propanol was
treated with 20.5 mL of 50% aqueous hydroxylamine and stirred until dissolved. Acetic
acid (6.41 mL) was added and the mixture was stirred for 15 hours at 50°C. Upon
cooling to ambient temperature, saturated NaHCO3 was added and the mixture was
concentrated en vacuo to remove isopropanol. The resulting aqueous mixture was
extracted three times with 250-mL portions of CHCl3. The organic extracts were
combined, washed with saturated NaHCO3, water, and brine, then dried over MgSO4,
filtered, and concentrated to yleld 20.5 g of crude product. Analysis by LC/MS revealed a
94:6 mixture of E and Z oximes, [M+H]+ = 764.
B. 15-Methylerythromycin A 9-[O-(1-isopropoxycyclohexyl)]oxime: The
crude oxime from above (20.5 g) was dissolved in 55 mL of CH2Cl2 and treated with 1, 1-
diisopropoxycyclohexane (27.3 mL) and pyridinium p-toluenesulfonate (9.8 gm) for 15
hours at ambient temperature. The mixture was diluted with 160 mL of CH2Cl2, then
washed sequentially with saturated NaHCO3, water, and brine. The organic phase was
dried with MgSO4, filtered, and evaporated to yleld a brown syrup. Chromatography on
silica gel (grathent from 2:1 to 3:2 hexanes/acetone + 1% Et3N) ylelded 18.0 g of product
C. 2', 4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-(1-
isopropoxycyclohexyl)oxime- A solution of 15-Methylerythromycin A 9-[O-(l-
isopropoxycyclohexyl)]oxime (9.00 g, 9.96 mmol) in 25 mL of CH2C12 was cooled on ice
under inert atmosphere and treated with a solution of chlorotrimethylsilane (1.89 mL) and
l-trimethylsilylimidazole (3.65 mL) in 8 mL of CH2Cl2. After 30 minutes, the reaction
was diluted with 250 mL of ethyl acetate and washed sequentially with saturated
NaHCO3, water, and brine. The organic phase was dried with MgSO4, filtered, and
evaporated. The crude product was purified by silica gel chromatography (grathent from
hexanes to 10:1 hexanes/acetone +1% Et3N), ylelding 7.8 g of product.
D. 6-O-methyl-2'. 4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-(1-
isopropoxycyclohexyl)]oxime: A solution of 2', 4"-biS-O-trimethylsilyl-15-
methylerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime(21.7 g, 20.7 mmol) in 41.4
mL of tetrahydrofuran was cooled to 10°C and treated with 41.4 mL of methyl sulfoxide
and 20.7 mL. of 2.0 M methyl bromide in ether under inert atmosphere. A mixture of
methylsulfoxide (41.4 mL) and 1.0 M potassium tert-butoxide in tetrahydrofuran (41.4
mL) was added at a rate of ca. 20 mL per hour. The reaction was monitored by thin-layer
chromatography (silica gel, 10:1 toluene/acetone), and was judged complete after addition
of 1.6 molar equivalents of base. The reaction was diluted with 200 mL of ethyl acetate
and 70 mL of saturated NaHCO3. The mixture was transferred to a separatory funnel,
diluted with 850 mL of ethyl acetate and 280 mL of saturated NaHCO3, then washed
sequentially with water and brine. The organic phase was dried with MgSO4, filtered
through Celite™, and evaporated to yleld 21.2 g of crude 6-O- methyl-2', 4"-bis-O- trimethylsiIyl-15-methylerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime. This was
carried on without further purification.
E. 6-O- methyl-15-methylerythromycin A 9-oxime: A solution of 6-O- methyl-2', 4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-(1-
isopropoxycyclohexyl)]oxime (21.2 g) in 110 mL of acetonitrile was treated with 55 mL
of water and 67 mL of acetic acid, and stirred for 8 hours at ambient temperature. The
mixture was concentrated en vacuo, then repeatedly concentrated after addition of toluene
to yleld 19.7 g of 6-O- methyl-15-methylerythromycin A 9-oxime.
F. 6-O- Methyl-15-methylervthromycin A: A solution, of 6-O-methyl-15-
methylerythromycin A 9-oxime (19.7 g) and sodium hydrosulfite (85%, 23.1 g) in 280
mL of 1:1 ethanol/water was placed under inert atmosphere. Formic acid (3.75 mL) was
added dropwise, and the mixture was stirred at 80°C for 4.5 hours. After cooling to
ambient temperature, the reaction was treated with saturated NaHCO3 and extracted three
times with 400-mL portions of ethyl acetate. The organic extracts were combined and
washed sequentially with saturated NaHCO3, water, and brine. The organic phase was
dried with MgSO4, filtered, and evaporated to yleld 15.1 g of 6-O- methyl-l5-
methylerythromycin A suitable for further conversion.
Example 7
Synthesis of 5-O-(2'-Acetyldesosaminyl)-10.11-anhydro-3-deoxy-3-oxo-6-O-methyl-14-
norerythronolide A (Anhydro form of Formula (6), Ra=Me. Rd=Me, Rc=Ac, Rb=H)
A. 5-O- Desosaminyl-6-O- methyl-14-norerythronolide A: A mixture of 6-O- methyl-14-norerythromycin A (77 mg), 0.073 ml of 12 N HC1 and water (2 ml) was
stirred at ambient temperature for 3 hours. The mixture was brought to pH 8 with 8 N
KOH, and extracted with ethyl acetate. The organic extract was washed with brine, dried
with MgSO4, filtered, and evaporated. The residue was chromatographed on silica gel
(3:l/hexanes:acetone, 1% triethylamine) to give pure product as a white solid (42 mg).
Mass spectrometry reveals [M+H]+ = 576.
B. 5-O-(2-Acetyldesosaminyl)-6-O- methyl-14-norerythronolide A: A
mixture of 5-O- desosaminyl-6-O- methyl-14-norerythronolide A (73 mg), potassium
carbonate(20 mg), acetic anhydride (14µl) and acetone (1 ml) was stirred at ambient
temperature for 18 hours. Ethyl acetate was added, washed with water and brine, dried
over MgSO4, filtered, and evaporated. The residue was chromatographed on silica gel
(3:l/hexanes:acetone, 1% triethylamine) to yleld the pure product (71 mg) as a white
solid. Mass spectrometry reveals [M+H]+ = 618.
C. 5-O-(2'-Acetyldesosaminyl)-3-deoxy-3-oxo-6-O- methyl-14-
norerythronolide A (Formula (1) RJ=OH. Rd=Me, R =Me, Rb=H. Rc=Ac): A solution of
5-O- (2'-acetyldesosaminyl)-6-O- methyl-14-norerythronolide A (99 mg) and l-(3-
dimethylaminopropyl)-3-ethylcarbodiidmide (EDC) hydrochloride (206 mg) in
dichloromethane (2 ml) was treated with DMSO (0.21 ml) and cooled to 5°C. A solution
of pyridinium trifluoroacetate (208 mg) in dichloromethane (2 ml) was added via a
syringe pump in 4 hours. Ethyl acetate was then added, washed with saturated NaHCO3,
water, brine, and dried over MgSO4, filtered, and evaporated. The residue was
chromatographed on silica gel (3:l/hexanes:acetone, 1% triethylamine) to yleld the pure
product (94 mg) as a white solid. Mass spectrometry reveals [M+H]+ = 616.
D. 5-O-(2'-Acetyldesosaminyl)-3-deoxy-3-oxo-11-O- methanesulfonyl-6-O-
methyl-14-norerythronolide A: To a solution of 5-O- (2'-acetyldesosaminyl)-3-deoxy-3-
oxo-6-O- methyl-14-norerythronolide A (93 mg) in dry pyridine (1 ml) was added
methanesulfonyl chloride (0.057 ml) at 5°C. After 3 hours at 5°C, the reaction was
warmed to ambient temperature and kept for an additiona115 hours. The mixture was
diluted with ethyl acetate, washed with saturated NaHCO3(2x), water (3x), brine, and
dried over MgSO4, filtered, and evaporated. The residue was chromatographed on silica
gel (2:l/hexanes:acetone, 1% triethylamine) to yleld the pure product (72 mg) as a white
solid. Mass spectrometry Teveals [M+H]+ = 695.
E- 5-O-(2'-Acetyldesosaminyl)-10.11-anhydro-3-deoxy-3-oxo-6-O-methyl-
14-norerythronolide A: A solution of 5-O-(2'-acetyldesosaminyl)-3-deoxy-3-oxo-11-O-
methanesulfonyl-6-O- methyl-14-norerythronolide A (73 mg) in acetone (1 ml) was
treated with diazabicycloundecene (32 µl) at ambient temperature for 18 hours. The
mixture was diluted with ethyl acetate, washed with saturated NaHCO3, water, brine, and
dried over MgSO4, filtered, and evaporated. The residue was chromatographed on silica
gel (2:1/hexanes:acetone, 1% triethylamine) to yleld the pure product (50 mg) as a white
solid. Mass spectrometry reveals [M+H]+ = 598. 13C-NMR (CDC13, 100 MHz): d
207.02, 204.50, 169.63, 168.72, 142.52, 139.40, 101.87, 80.61, 80.02, 77.14, 72.66,
71.48, 69.09, 63.56, 51.35, 50.56, 47.12, 40.61, 39.73, 37.36, 30.36, 21.32, 21.06, 20.96,
20.67, 18.45, 14.34, 13.89, 13.55, 13.45.
Example 8
Synthesis of 2'-O- Benzoyl-6-O- methyl-3-descladinosyl-3-oxo-10.11-anhydro-14, 15-
dehydroerythromycin A (Anhydro form of Formula (6). Rd=allyl, Ra=Me, Rb=H,
Rc=Benzoyl)
A. 2'-O- Benzoyl-6-O-methyl-14.15-dehydroerythromycin A
A solution of 6-O- methyl-14, 15-dehydroerythromycin A (668 mg), benzoic
anhydride (385 mg), and triethylamine (0.25 mL) in 3.6 mL of CH2Cl2 was stirred for 2
days. After addition of saturated NaHCO3, the mixture was extracted three times with
CH2Cl2. The organic extracts were combined and evaporated to dryness, and the product
was purified by silica chromatography (90:9:1 toluene/acetone/Et3N) to give 477 mg of
product; LC-MS shows [M+H]+ = 850.6.
B. 2'-O- Benzoyl-6-O- methyl-4", 11 -bis( O-methanesulfonyl)-14, 15-
dehydroerythromycin A
A solution of 2'-O- ben2oyl-6-O-methyl-14, 15-dehydroerythromycm A (549 mg)
and methanesulfonyl chloride (0.50 mL) in 2.39 mL of pyridine was stirred for 24 hours,
then diluted with CH2Cl2 and saturated NaHCO3. The mixture was extracted three times
with CH2Cl2. The organic extracts were combined and evaporated to dryness, and the
product was purified by silica chromatography (90:9:1 toluene/acetone/Et3N) to give 530
mg of product; LC-MS shows [M+H]+ = 1006.5.
C. 2'-O-Benzoyl-6-O-methyl-4"-O-methanesulfonyl-10, 11 -anhydro-14.15-
dehydroerythromycin A
A mixture of 2'-O- benzoyl-6-O- methyl-4", 11-bis(O-methanesulfonyl)14, 15-
dehydroerythromycin A (59 mg) and diazabicycloundecene (0.018 mL) in 0.195 mL of
acetone was stirred for 24 hours, then dried in vacuo. The product was purified by silica
chromatography (90:9:1 toluene/acetone/Et3N) to give 50 mg of product; LC-MS shows
[M+H]+=910.5.
D. 2'-O-Benzoyl-6-O-methyl-3-descladinosyl-10.11-anhydro-14.15-
dehydroerythromycin A
A mixture of 2'-O-benzoyl-6-O-methyl-4"-O-methanesulfonyl-10, 11-anhydro-
14, 15-dehydroerythromycin A (337 mg), 1.5 mL of acetonitrile, and 6.9 mL of 3 N HC1
was stirred for 22 hours. The acetonitrile was removed in vacuo, the pH of the aqueous
residue was adjusted to 12 by addition of NaOH, and the product was extracted using 4
portions of CH2Cl2. The combined extracts were dried and evaporated. The product was
purified by silica chromatography (grathent from 96:4 CH2Cl2/MeOH to 95:4:1
CH2Cl2/MeOH/Et3N) to give 197 mg, [M+H]+ = 674.4.
E. 2'-O-Benzoyl-6-O-methyl-3-descladinosyl-3-oxo-10, ll-anhydro-14.15-
dehydroerythromycin A
A suspension of 2'-O-ben2oyl-6-O-methyl-3-descladinosyl-10, l l-anhydro-14, 15-
dehydroerythromycin A (226 mg) and the Dess-Martin periodinane (427 mg) in 14.6 mL
of CH2Cl2 (14.6 mL) was stirred for 1 hour. The mixture was diluted with CH2C12 and
saturated NaHCO3. The product was extracted using 3 portions of CH2C12, and the
extracts were combined, dried, and evaporated. Silica gel chromatography (90:9:1
toluene/acetone/Et3N) ylelded the product, 168 mg. [M+H]+= 672.4. 13C-NMR (CDC13,
100 MHz): d 206.78, 203 (br), 168.19, 165.08, 141.36, 139.58, 132.74, 131.51, 130.46,
129.79, 128.25, 120.18, 102.09. 80.79, 80.40, 78.70, 72.52, 71.91, 69.19, 63.76, 51.10,
50.54, 47.08, 40.73, 39.87, 37.77, 31.23, 22.13, 20.98, 18.52, 14.28, 14.15, 13.55.
Example 9
Synthesis of 5-O-(2'-acetyldesosaminyl)-10,11-anhydro-3-deoxy-3-oxo-6-O-
methyl-15-methylerythronolide A (anhydro form of Formula (6V. Rc=Mc. Rd=propyl,
A. 6-O- methyl-3-descladinosyl-l 5-methylerythromycin A
A mixture of 6-O- methyl-15-methylerythromycin A (15.1 g) and 280 mL of 0.5 N
HC1 was stirred at ambient temperature for 3 hours. The pH was adjusted to 9 by
addition of 6 N NaOH, and the resulting precipitate was collected by vacuum filtration,
washed with water, and dried. The filtrate was extracted three times with 400-mL
portions of ethyl acetate. The organic extracts were combined, washed sequentially with
saturated NaHCO3, water, and brine, then dried over MgSO4, filtered, and evaporated to
provide further product. The combined crude products were chromatographed on silica
gel to yleld 9.35 g of pure 6-O- methyl-3-descladinosyl-15-methylerythromycin A. ES-
LC/MS shows [M+H]+ = 605.
B. 2'-O- Acetyl-6-O- methyl-3-descladinosyl-15-methylerythromycin A
A solution of acetic anhydride (2.92 mL) in 35 mL of ethyl acetate was added
dropwise to a solution of 6-O- methyl-3-descladinosyl-15-methylerythromycin A (9.35 g)
in 40 mL of ethyl acetate. The mixture was stirred for 30 minutes after completion of
addition, then concentrated. Chromatography on silica gel (2:1 hexanes/acetone) gave
8.35 g of 2'-O- acctyl-6-O- methyl-3-descladmosyl-15-methylerythromycin A. ES-LC/MS
shows [M+H]+ = 647.
C. 2'-O- Acetyl-6-Q-methyl-3-descladinosyl-3-oxo-l 5-methylerythromycin A
A solution of 2'-O- acetyl-6-O- methyl-3-descladmosyl-15-methylerythromycin A
(8.3 g) and l-ethyl-3-(dimethylaminopropyl)carbodimide hydrochloride (16.51 g) in 64
mL of dichloromethane and 15.47 mL of methylsulfoxide was placed under inert
atmosphere and cooled on ice. A solution of pyridinium trifluoroacetate (16.63 g) in 64
mL of dichloromethane was added at a rate such that addition would be complete in 4
hours, and the reaction was monitored by thin-layer chromatography. Complete reaction
was observed after addition of 73% of the solution, and so the reaction was then
quenched by addition of 600 mL of ethyl acetate and 200 mL of saturated NaHCO3. The
organic layer was collected and washed sequentially with saturated NaHCO3, water, and
brine, then dried over MgSO4, filtered, and evaporated to yleld 8.4 g of crude product.
Chromatography on silica gel (3:1 hexanes/acetone) gave 6.75 g of 2'-O- acetyl-6-O- methyl-3-descladinosyl-3-oxo-15-methylerythromycin A. ES-LC/MS shows [M+H]+ =
645.
D. 2'-O-Acetyl-6-O-methyl-3-descladinosyl-3-oxo-11 -O-methanesulfonyl-15-
methylerythromycin A
Methanesulfonylchloride (5.68 mL) was added dropwise to a solution of 2'-O- acetyl-6-O- methyl-3-descladinosyl-3-oxo-15-methylerythromycin A (6.73 g) in 35 mL of
pyridine at 0°C. The mixture was brought to ambient temperature and quenched by
addition of 700 mL of ethyl acetate and 200 mL of saturated NaHCO3- The organic layer
was collected and washed sequentially with saturated NaHCO3, water, and brine, then
dried over MgSO4, filtered, and evaporated to yleld 8.2 g of crude product.
Chromatography on silica gel (5:2 hexanes/acetone) gave 5.04 g of 2'-O- acetyl-6-O- methyl-3-descladinosyl-3-oxo-11-O- methanesulfonyl-15-methylerythromycin A. ES-
LC/MS shows [M+H]+ = 723.
E. 2'-O- Acetyl-6-O- methyl-3-descladinosyl-3-oxo-10, 11 -anhydro-15-
methylerythromycin A
l, 8-Diazabicyclo[5.4.0]undec-7-ene (5.22 mL) was added dropwise to a solution
of 2'-O- acetyl-6-O- methyl-3-descladinosyl-3-oxo-11-O-methanesulfonyl-15-
methylerythromycin A (5.03 g) in 23 mL of acetone. The solution was concentrated after
4.5 hours, and the residue was chromatographed on silica gel (5:2 hexanes/acetone) to
give 3.72 g of 2, -O-acetyl-6-O-methyl-3-descladinosyl-3-oxo-10, 11-anhydro-15-
methylerythromycin A. ES-LC/MS shows [M+H]+ = 627.
Example 10
Synthesis of S-O- (2'-acetyldesosaminyl)-l 0, 11 -anhydro-3, 6-dldeoxy-3-oxo-15-
methylerythronolide A (Formula (6), anhydro form, Rd=propyl, OR, replaced
by H, Rb=H, Rc=Ac)
To a solution of 6-deoxy-15-methyl erythromycin C (220mg, 0.307mmol) in
dichloromethane (5mL) were given potassium carbonate (50mg) and acetic anhydride
(100 L, 0.9mmol), and the reaction was stirred at room temperature for 16 hours. The
solution was filtered, sodium hydroxide (IN, 25mL) and brine (25mL) added and the
aqueous layer was extracted with ethyl acetate 6 times. The combined organic layers
were dried with sodium sulfate, filtered, and the solvent removed in vacuo. The crude
product the 2' acetylated form of the starting material was carried en to the next step.
The crude product was dissolved in pyridine (5mL) and mesyl chloride (70L,
0.9mmol) was added. The reaction was stirred at -20°C for 2 days, poured on sodium
hydroxide (IN, 25mL) and brine (25mL) and the aqueous layer was extracted with ethyl
acetate 6 times. The combined organic layers were dried with sodium sulfate, filtered,
and the solvent removed in vacuo. The residue was purified by chromatography on silica
gel (toluene/acetone = 3:1, 1% ammonium hydroxide) to yleld 11, 4" dimesylated form
(190 mg, 68% over two steps).
The 11, 4" dimesylated form (190 mg, 0.21 mmol) was dissolved in acetone (7mL)
and DBU (63L, 0.42 mmol) was added, and the reaction was stirred at room temperature
over night. The mixture was poured on sodium hydroxide (1N, 25mL) and brine (25mL)
and the aqueous layer was extracted with ethyl acetate 6 times. The combined organic
layers were dried with sodium sulfate, filtered, and the solvent removed in vacuo. The
crude product, the 10, 11-dehydro form of 6-deoxy-15-methyl erythromycin was carried
on to the next step.
To the crude product from the above step was added hydrochloric acid (30 mL,
3N) and ethanol (2mL) and the mixture was stirred vigorously for 6 hours. Sodium
hydroxide (5mL, 10N) was added and the aqueous layer was extracted with ethyl acetate
6 times. The combined organic layers were dried with sodium sulfate, filtered, and the
solvent removed in vacuo. The crude product, the anhydro form of formula (6) (but with
OH at position 3) where Rd=propyl, ORa is replaced by H, Rb=Rc=H, was carried on to
the next step.
To the crude product from the above step in dichloromethane (5mL) was added
acetic anhydride (50L, 0.45mmol) and potassium carbonate (l00mg) and the mixture was
stirred vigorously for 9 hours. The reaction was filtered, sodium hydroxide (20mL, IN)
and brine (25mL) were added and the aqueous layer was extracted with ethyl acetate 6
times. The combined organic layers were dried with sodium sulfate, filtered, and the
solvent removed in vacuo. The residue was purified by chromatography on silica gel
(toluene/acetone = 3:1, 1% ammonium hydroxide) to yleld the 2' acetylated form of the
starting material (110 mg, 89% over three steps).
The product of the above step (11 0mg, 0.184 mmol) was dissolved in
dichloromethane (10mL) and Dess-Martin reagent (220 mg, 0.53 mmol) was added. The
reaction was stirred at room temperature for 45 min. The reaction was quenched with
Sodium hydroxide (20mL, IN) and brine (25mL) and the aqueous layer was extracted
with ethyl acetate 6 times. The combined organic layers were dried with sodium sulfate,
filtered, and the solvent removed in vacuo. The residue was purified by chromatography
on silica gel (toluene/acetone, grathent = 6:1-3:1, 1% ammonium hydroxide) to yleld the
compound of formula (6), anhydro form, where Rd=propyl, ORa is replaced by H, Rb=H,
Rc=Ac (94 mg, 86%).
Example 11
I. Compound of Formula (4): Rd=propyl, Ra=allyl
Step 1. Allylation of Intermediate Antibiotic at 6-OH: A solution of 2',4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-(1-isopropoxycyclohexyl)]oxime (formula
(I) (R, is OH, Rd is propyl, protected at 2' and 4" with trimethylsilyl and at C9=O by the
isoproxycyclohexyl oxime)) (7.8 g, 7.44 mmol) in 30 mL of tetrahydrofuran was cooled
on ice and treated with 30 mL of methylsulfoxide and 2.58 mL of freshly distilled allyl
bromide under inert atmosphere. A mixture of methylsulfoxide (29.8 mL) and 1.0 M
potassium tert-butoxide in tetrahydrofuran (29.8 mL) was added at a rate of 1.33 molar
equivalents of base per hour. The reaction was monitored by thin-layer chromatography
(silica gel, 10:1 toluene/acetone), and was judged complete after addition of 3.6 molar
equivalents of base. The reaction was diluted with 700 mL of ethyl acetate and washed
sequentially with saturated NaHCO3, water, and brine. The organic phase was dried with
MgSO4f filtered, and evaporated to yleld 8.08 g of crude 6-O-allyl-2',4"-bis-O-
trimethylsilyl-15-methylerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime. This was
carried on without further purification.
Step 2: A solution of 6-O- allyl-2',4"-bis-O- trimethylsilyl-15-methylerythromycin
A 9-[O-(l-isopropoxycyclohexyl)]oxime (8.08 g) in 42 mL of acetonitrile was treated
with 21 mL of water and 24 mL of acetic acid, and stirred for 18 hours at ambient
temperature. The mixture was concentrated after addition of 2-propanol, then repeatedly
after addition of toluene to yleld 7.7 g of crude product. Chromatography on silica gel
(grathent from 2:1 to 1:1 hexanes/acetone + 1% Et3N) gave 3.75 g of 6-O- allyl-15-
methylerythromycin A 9-oxime.
Step 3: A solution of 6-O- allyl-15-methylerythromycin A 9-oxime (3.75 g) and
sodium hydrosulfite (85%, 5.37 g) in 66 mL of 1:1 ethanol/water was placed under inert
atmosphere. Formic acid (0.845 mL) was added dropwise, and the mixture was stirred at
80°C for 3.5 hours. After cooling to ambient temperature, the reaction was adjusted to
pH 10 with 6 N NaOH and extracted three times with 150-mL portions of ethyl acetate.
The organic extracts were combined and washed sequentially with saturated NaHCO3,
water, and brine. The organic phase was dried with MgSO4, filtered, and evaporated to
yleld 3.42 g of 6-O- allyl-15-methylerythromycin A suitable for further conversion.
II. Compound of Formula (4): Rd=Me. Ra=allyl
Step 1: Allylation of Intermediate Antibiotic at 6-OH: A solution of 2',4"-bis-O- trimethylsilyl-14-norerythromycin A 9-[O-(1-isopropoxycyclohexyl)]oxime, Formula (I),
(Ra is OH, Rd is methyl, protected at 2' and 4" with trimethylsilyl and at C9=O by the
isoproxycyclohexyl oxime) (202 mg) in tetrahydrofuran (0.4 mL), DMSO (0.4 mL), and
ether (0.04 ml) was cooled to 10°C and treated with 0.035 mL of freshly distilled allyl
bromide under inert atmosphere. A mixture of methylsulfoxide (0.4 mL) and 1.0 M
potassium tert-butoxide in tetrahydrofuran (0.4 mL) was added at a rate 0.22 mL/hour.
The reaction was monitored by thin-layer chromatography (silica gel, 5:1 toluene/acetone.
The reaction was diluted with ethyl acetate and washed sequentially with saturated
NaHCO3, water, and brine. The organic phase was dried with MgSO4, filtered, and
evaporated to yleld 222 mg of crude 6-O-allyl-2', 4"-bis-O- trimerhylsilyl-14-
norerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime. This was carried on without
further purification.
Step 2: A solution of 6-O- allyl-2',4"-bis-O- trimethylsilyl-14-norerythromycin A
9-[O-(l-isopropoxycyclohexyl)]oxime (222 mg) in 4 mL of acetonitrile was treated with
2 mL of water and 2.4 mL of acetic acid, and stirred for 18 hours, at ambient temperature.
The mixture was concentrated after addition of 2-propanol, then repeatedly after addition
of toluene to yleld 220 mg of crude 6-O- allyl-l4-norerythromycin A 9-oxime.
Step 3: A solution of 6-O- allyl-14-norerythromycin A 9-oxime (220 mg) and
sodium hydrosulfite (85%, 322 mg) in 4 mL of 1:1 ethanol/water was placed under inert
atmosphere. Formic acid (0.050 mL) was added dropwise, and the mixture was stirred at
80°C for 15 hours. After cooling to ambient temperature, the reaction was adjusted to pH
10 with 6 N NaOH and extracted three times with 150-mL portions of ethyl acetate. The
organic extracts were combined and washed sequentially with saturated NaHCO3, water,
and brine. The organic phase was dried with MgSO4, filtered, and evaporated to yleld
156 mg of 6-O- allyl-14-norerythromycin A suitable for further conversion.
Other embodiments: In a similar manner, compounds of formula (4) wherein Y
and Z are, together, =O, Ra is allyl, is prepared from an intermediate where Rd is butyl,
benzyl, vinyl, or 3-hydroxybutyl.
Example 12
Conversion to Formula (4) to Formula (6)
Step 1. A mixture of the compound prepared in Example 11, II (77 mg, crude),
0.073 ml of 12 N HC1 and water (2 ml) was stirred at ambient temperature for 3 hours.
The mixture was brought to pH 8 with 8 N KOH, and extracted with ethyl acetate. The
organic extract was washed with brine, dried with MgSO4, filtered, and evaporated. The
residue was chromatographed on silica gel (3:1/hexanes:acetone, 1% triethylaminc) to
give pure product as a white solid (42 mg).
Step 2. To protect the 2' OH, a mixture the above compound (73 mg), potassium
carbonate (20 mg), acetic anhydride (14µl) and acetone (1 ml) was stirred at ambient
temperature for 18 hours. Ethyl acetate was added, washed with water and brine, dried
over MgSO4, filtered, and evaporated. The residue was chromatographed on silica gel
(3:1/hexanes:acetone, 1% triethylamine) to yleld the pure product (71 mg) as a white
solid.
Step 3. A solution of the compound resulting from step 2 (99 mg) and l-(3-
dimethylaminopropyl)-3-ethylcarbodiidmide (EDC) hydrochloride (206 mg) in
dichloromethane (2 ml) was treated with DMSO (0.21 ml) and cooled to 5°C. A solution
of pyridinium trifluoroacetate (208 mg) in dichloromethane (2 ml) was added via a
syringe pump in 4 hours. Ethyl acetate was then added, washed with saturated NaHCO3,
water, brine, and dried over MgSO4, filtered, and evaporated. The residue was
chromatographed on silica gel (3:1/hexanes:acetone, 1% triethylamine) to yleld the pure
compound of formula (6) (94 mg, R8 is allyl, Rc is acetate and Rd is CH3).
Step 4. To deprotect 2' OH, a solution of the compound resulting from step 3 (94
mg) in 5 mL methanol was stirred at room temperature for 24 hours. The solvent was
removed in vacuo to give the desired compound of formula (6) (R, is allyl, Rc is H, and
Rd is CH3).
Other embodiments: In a similar manner, compounds of formula (4) wherein Ra
is allyl, Rc is H, and Rd is propyl, butyl, benzyl, vinyl, or 3-hydroxybutyl is prepared.
Example 13
Preparation of Compounds of Formula (5)
The compound of formula (4), prepared as the 6-allyl derivative in Example 11, is
protected at the 2' position, treated with acid and dehydrated, then deprotected to obtain
the compound of formula (5), as shown in Figure 1, wherein Rc is H, and Ra is allyl.
Similarly, compounds of formula (6) wherein Rd is propyl, butyl, benzyl, vinyl, or
3-hydroxybutyl, are prepared as described above using as starting material the compounds
of formula (T) wherein Rd is as set form above.
Example 14
Conversion of =O at Position 9 to =NOH
According to the procedure of Example 6A, the carbonyl at position 9 of
erythromycins are converted to the corresponding oximes.
Example 15
Conversions at -ORa
A. Allyl? Propyl
A solution of any of the compounds prepared above (0.2 mmol) in ethanol is
flushed with nitrogen and 10% palladium on carbon (20 mg) added. The mixture is then
flushed with, hydrogen and the reaction mixture stirred overnight under positive hydrogen
pressure. The reaction mixture is filtered and concentrated in vacuo to give a glass.
Chromatography on silica gel (95:5:0.5 dichloromethane-methanol-ammonia) gives the
propyl compounds as white solids.
B. Allyl? -CH2CHO
Ozone is passed through a -78°C solution in dichloromethane (100 mL) of any of
the compounds resulting above (4.0 mmol) for 45 minutes. The reaction mixture is then
flushed with nitrogen for 10 minutes. Dimethyl sulfide (1.46 mL, 20 mmol) is added at
-78°C and the reaction mixture stirred for 30 minutes at 0°C. The reaction mixture is
concentrated in vacuo to give a white foam which is used without further purification by
heating a solution of the compound in THF (40 mL, 4.0 mmol) and triphenylphosphine
(2.62 g, 10.0 mmol) at 55°C for 2.5 hours. The reaction mixture is concentrated in vacuo
to give a white foam. Chromatography on silica gel (1:1 acetone-hexane, then 75:25:0.5
acetone-hexane-triethylamine) gives the desired compound as a white solid.
C. Allyl? -CH2CH=NOH
To a solution in methanol (5 mL) of the compound prepared in B wherein Ra is
-CH2CHO, (0.08 mmol) is added triethylamine (31 µL, 0.225 mmol) and hydroxylamine
hydrochloride (7.7 mg, 0.112 mmol) and the reaction mixture stirred for 6 hours at
ambient temperature. The reaction mixture is taken up in ethyl acetate and washed with
aqueous 5% sodium bicarbonate and brine, dried over sodium sulfate, and concentrated in
vacuo to give a clear glass. Chromatography on silica gel (95:5:0.5 dichloromethane-
methanol-ammonia) gives the compound as a white solid.
D. -CH2CH=NOH? -CH2CN
To a solution under nitrogen of the compound prepared in C (0.267 mmol) in THF
(5 mL) is added diisopTopylcarbodiimide (83 µL, 0.534 mmol) and CuCl (2.7 mg, 0.027
mmol) and the reaction mixture is stirred overnight at ambient temperature. The reaction
mixture is taken up in ethyl acetate and washed with aqueous 5% sodium bicarbonate and
brine, dried over sodium sulfate, and concentrated in vacuo to give a clear glass.
Chromatography on silica gel (95:5:0.5 dichloromethane-methanol-ammonia) gives the
desired compound as a white solid.
E. -CH2CHO? -CH2CH2 NH2
To a solution in methanol (10 mL) of the compound prepared in B (0.276 mmol)
is added ammonium acetate (212 mg, 2.76 mmol) and the mixture is cooled to 0°C.
Sodium cyanoborohydride (34 mg, 0.553 mmol) is added and the reaction mixture stirred
for 30 hours at 0°C. The reaction mixture is taken up in ethyl acetate and washed with
aqueous 5% sodium carbonate, aqueous 2% tris(hydroxymethyl)aminomethane, and
brine, dried over sodium sulfate, filtered, and concentrated in vacuo. Chromatography on
silica gel (90:10:0.5 dichloromethane-methanol-ammonia) gives the desired compound as
a white solid.
F. -CH2CHO? -CH2CH2NHCH2-Phenyl
To a 0°C solution in methanol (10 mL) of the compound prepared in B (0.200
mmol) is added acetic acid (114 µL, 2.00 mmol) and benzylamine (218 µL, 2.00 mmol)
and the mixture is stirred for 10 minutes. Sodium cyanoborohydride (24.8 mg, 0.400
mmol) is added and the reaction mixture stirred for 16 hours. Additional sodium
cyanoborohydride (24.8 mg, 0.400 mmol) is then added and stirring continued for 5
hours. The reaction mixture is taken up in ethyl acetate and washed with aqueous 5%
sodium carbonate, aqueous 2% tris(hydroxymethyl)aminomethane, and brine, dried over
sodium sulfate, filtered, and concentrated in vacuo. Chromatography on silica gel
(95:5:0.5 dichloromethane-methanol-ammonia) followed by a second chromatography
(50:50:0.5 acetone-hexanes-triethylamine) gives the desired compound as a white foam.
G. -CH2CHO?CH2 CH2NHCH2CH2-Phenyl
To a 0°C solution in methanol (10 mL) of the compound prepared in B (0.200
mmol) is added acetic acid (114 µL, 2.00 mmol) and phenethylamine (218 µL, 2.00
mmol) and the mixture stirred for 10 minutes. Sodium cyanoborohydride (24.8 mg, 0.400
mmol) is added and the reaction mixture stirred for 16 hours. The reaction mixture is
taken up in ethyl acetate and washed with aqueous 5% sodium carbonate, aqueous 2%
tris(hydroxymethyl)aminomethane, and brine, dried over sodium sulfate, filtered, and
concentrated in vacuo. Chromatography on silica gel (90:10:0.5 dichloromethane-
methanol-ammonia) gives the desired compound.
H. -CH2CHO? -CH2CH2NHCH(CO2CH3)CH2-Phenyl
To a 0°C solution in medianol (10 mL) of the compound prepared in B (0.200
mmol) is added L-phenylalanine methyl ester hydrochloride (129 mg, 0.600 mmol) and
the mixture stirred for 10 minutes. Sodium cyanoborohydride 924.8 mg, 0.400 mmol) is
added and the reaction mixture stirred for 22 hours. The reaction mixture is taken up in
ethyl acetate and washed with aqueous 5% sodium carbonate, aqueous 2%
tris(hydroxymethyl)aminomethane, and brine, dried over sodium sulfate, filtered, and
concentrated in vacuo. Chromatography on silica gel (95:5:0.5 dichloromethane-
methanol-ammonia) gives the desired compound.
I. -CH2CHO? -CH2CH2NHCH2-(4-pyridyl)
The desired compound is prepared according to the method in G, except
substituting 4-aminomethylpyridine for phenethylamine.
J. -CH2CH2NH2 ? -CH2CH2NHCH2 -(4-quinolyl)
To a solution of the compound prepared in E (0.15 mmol) in methanol (2 mL) is
added 4-quinolinccarboxaldehyde (23 mg, 0.15 mmol), acetic acid (8.6 µL, 0.15 mmol),
and sodium cyanoborohydride (9.4 mg, 0.15 mmol) and the reaction mixture is stirred for
15 hours. The reaction mixture is taken up in ethyl acetate and washed with aqueous 5%
sodium carbonate, aqueous 2% tris(hydroxymethyl)ammomethane, and brine, dried over
sodium sulfate, filtered, and concentrated in vacuo. Chromatography on silica gel
(95:10:0.5 dichloromethane-methanol-ammonia) gives the desired compound.
K. Allyl ? -CH2CH=CH-Phenyl
To a solution under nitrogen of the 2' protected compound prepared in Example
10 (1.00 mmol), palladium(II)acetate (22 mg, 0.100 mmol), and triphenylphosphme (52
mg, 0.200 mmol) in acetonitrile (5 mL) was added iodoben2ene (220 µL, 2.00 mmol) and
triethylamine (280 µL, 2.00 mmol) and the mixture is cooled to -78°C, degassed, and
sealed. The reaction mixture is then warmed to 60°C for 0.5 hours and stirred at 80°C for
12 hours, taken up in ethyl acetate and washed twice with aqueous 5% sodium
bicarbonate, once with aqueous 2% tris(hydroxymethyl)aminomethane, and once with
brine, dried over sodium sulfate, filtered, and concentrated in vacuo. Chromatography on
silica gel (95:5:0.5 dichloromethane-methanol-ammonia) gives the desired compound.
Deprotection is accomplished by heating in methanol.
Other embodiments of formulas (4)-(6) where Rb is H, Rc is H, and Rd is propyl,
butyl, benzyl, vinyl, or 3-hydroxybutyl are those wherein R, is:
Any of the foregoing compounds can be converted to the corresponding
derivatives wherein Y and Z are together =NOH in the manner described in Example 14
above.
Example 16
Preparation of Compound of Formula (1) L is CO. T is O, Ra = -CH2CH=CH2, Rc is H
Step 1. Protection at 2'-OH to form intermediate compound of compound (6)
having hydroxyl group at C-3, Ra, is allyl and Rc is benzoyl.
To a solution of the product of Example 12 or other embodiment thereof wherein
Rd is propyl, butyl, benzyl, vinyl or 3-hydroxybutyl (2.49 g, 4.05 mmol) in
dichloromethane (20 mL) is added benzoic anhydride (98%, 1.46 g, 6.48 mmol) and
triethylarnine (0.90 mL, 6.48 mmol) and the white suspension is stirred for 26 hours at
ambient temperature. Aqueous 5% sodium carbonate is added and the mixture is stirred
for 20 minutes. The mixture is extracted with dichloromethane. The organic phase is
washed with aqueous 5% sodium bicarbonate and brine, dried over sodium sulfate and
concentrated in vacuo to give a white foam. Chromatography on silica gel (30% acetone-
hexanes) gives the protected compound.
Step 2. Oxidation to form compound (6) Ra, is allyl, Rc is benzoyl.
To a -10°C solution under N2 of N-chlorosuccinimide (0.68 g, 5.07 mmol) in
dichloromethane (20 mL) is added dimethylsulfide (0.43 mL, 5.92 mmol) over 5 minutes.
The resulting white slurry is stirred for 20 minutes at -10°C and then a solution of the
compound resulting from step 1 (2.43 g, 3.38 mmol) in dichloromethane (20 mL) is
added and the reaction mixture is stirred for 30 minutes at -10 to -5°C. Triethylarnine
(0.47 mL, 3.38 mmol) is added dropwise over 5 minutes and the reaction mixture is
stirred for 30 minutes at 0°C The reaction mixture is extracted with dichloromethane.
The organic phase is washed twice with aqueous 5% sodium bicarbonate and once with
brine, dried over sodium sulfate, and concentrated in vacuo to give a white foam.
Chromatography on silica gel (30% acetone-hexanes) gives the oxidized compound.
Step 3: Form cyclic carbonate of compound of formula (1) from Illustrative
Scheme 5: Ra is -CH2CH=CH2, Rc is benzoyl.
To a -35°C solution under nitrogen in THF (60 mL) of the compound prepared in
step 2 (3.58 g, 5.00 mmol) is added sodium hexamethyldisilazide (1.0 M in THF, 5.5 mL,
5.5 mmol) and the resulting white suspension is stirred for 30 minutes. A solution of
carbonyldiimidazole (4.05 g, 25 mmol) in THF (40 mL) is added dropwise over 20
minutes at -35°C and then the cold bath is removed and the reaction mixture is stirred for
30 minutes. The reaction mixture is taken up in ethyl acetate and washed with aqueous
5% sodium bicarbonate and brine, dried over sodium sulfate, filtered, and concentrated in
vacuo. Chromatography on silica gel (30% acetone-hexane) gives the dehydrated
compound (2.6 g) as a white foam. (M+H)+ is 744.
Step 4. Deprotection to form compound of Formula (1): L is CO. T is Q. R, is
-CH2CH=CH2, Rc is H.
A solution of the compound resulting from step 3 (719 mg, 1.0 mmol) in
methanol (20 mL) is stirred at reflux for 6 hours. The reaction mixture is concentrated in
vacuo and the residue is purified by chromatography on silica gel (95:5:0.5
dichloromethane-methanol-ammonia) to give the desired compound.
Example 17
Compound of Formula (1) L is CO. T is O, R, is -CH, CH=CH-Phenyl.
A. Form cyclic carbonate of compound of formula (1) from Illustrative
Scheme 5: R, is -CH2CH=CH-Phenyl. Rc is benzoyl.
A solution of the compound prepared in Example 15, step K or other
embodiments wherein Rd is propyl, butyl, benzyl, vinyl, or 3-hydroxybutyl (150 mg, 0.20
mmol) in THF (5 mL) is cooled to -35°C and flushed with nitrogen. Lithium
hexamethyldisilazide (1.0 M in THF, 0.22 mL, 0.22 mmol) over 2 minutes at -35°C. The
reaction mixture is stirred for 10 minutes at -35°C and then a solution of
carbonyldiimidazole (162 mg, 1.00 mmol) in THF (3 mL) is added dropwise over 2
minutes. The cold bath is removed and the reaction mixture is stirred for 30 minutes..
The reaction mixture is cooled to 0°C and aqueous 0.5 M KH2PO4 is added. The mixture
is extracted with ethyl acetate and the organic phase is washed with brine, dried over
sodium sulfate, and concentrated in vacuo. Chromatography on silica gel (30% acetone-
hexane) gives the dehydrated compound.
B. Deprotection to form compound of Formula (1): L is CO. T is O, Ra is -CH2CH=CH-Phenyl. Rc is H
Deprotection of the compound prepared in step A is accomplished by heating in
methanol according to the procedure of Example 16, step 4.
Using the procedures described in the preceding examples and schemes and
methods known in the synthetic organic chemistry art, the compounds of Formula (1)
wherein L is CO and T is O can be prepared. These compounds include one of the Ra
substituents listed below:
Example 18
Preparation of Compound of Formula (1): L is CO, T is NH. Ra-is -CH2CH=CH2),
Step 1: Preparation to form 10. 11 anhydro form of intermediate compound (6):
Ra is -CH2CH=CH2, Rc is benzoyl.
A. 6-O-allyl-3-descladinosyl-15-methyl-erythromycin A
A mixture of 6-O-allyl-l 5-methylerythromycin A (6.58 g) and 125 mL of 0.5 N
HC1 was stirred at ambient temperature for 20 hours. The pH was adjusted to 10 by
addition of 6 N NaOH, and the mixture was extracted three times with 225-mL portions
of ethyl acetate. The organic extracts were combined, washed sequentially with saturated
NaHCO3, water, and brine, then dried over MgSO4, filtered, and evaporated. The crude
product was chromatographed on silica gel (3:2 toluene/acetone + 1% Et3N) to yleld 3.04
g of pure 6-O-allyl-3-descladinosyl-15-methylerythromycin A. ES-LC/MS shows
[M+H]+ = 617.
B. 2'-O-Benzoyl-6-O-allyl-3-descladinosyl-15-methyl-erythromycin A
6-O-Allyl-3-descladinosyl-15-methylerythromycin A (2.43 g, 3.86 mmol, 1.00 eq)
and benzoic anhydride (1.78 g, 7.72 mmol, 2.00 eq) were placed in a round-bottomed
flask and flushed with N2. Ethyl acetate (17.5 mL) was added. The solution was stirred
for 3.5 h and then diluted with 400 mL of EtOAc and washed twice with 150 mL of
saturated aqueous NaHCO3 and once each with 150 mL of water and brine. The organic
phase was dried over MgSO4, filtered, and concentrated. Purification by flash
chromatography over silica gel (3:1 hexanes:acetone +1% Et3N) gave 1.94 g (68.1%) of
the desired product as a white solid. ES-LC/MS shows [M+H]+ = 721 13C NMR (100.6
MHz, CDC13) d 219.4, 174.3, 165.4, 135.3, 132.6, 130.8, 129.7,128.2,117.2, 99.7, 80.7,
79.0, 77.9, 77.7, 75.1, 74.3, 72.3, 69.0, 64.7, 63.3/, 45.6, 43.9, 40.7, 37.9, 37.7, 35.7, 32.1,
30.8, 21.1, 20.2,19.3, 18.1, 16.3,15.1,14.0,12.4, 7.7.
C. 2'-O- Benzoyl-6-O- allyl-3-descladinosyl-3-oxo-15-methyl-erythromycin A
N-Chlorosuccinimide (0.510 g, 3.82 mmol, 1.50 eq) was dissolved in 13 mL of
anhydrous CH2C12 and cooled to -10 °C under N2. Methyl sulfide (0.328 mL, 4.46
mmol, 1.75 eq) was added, and the reaction was stirred for 15 min. A solution of 2'-O- ben2oyl-6-O- allyl-3-descladinosyl-15-methylcTythromycin A (1.87 g, 2.55 mmol, 1.00
eq) in 13 mL of anhydrous CH2Cl2 was added dropwise. After 30 min, freshly distilled
Et3N (0.355 mL, 2.55 mmol, 1.00 eq) was added; and the reaction was brought up to 0 °C
over 30 min. The reaction mixture was diluted with 400 mL EtOAe and washed
successively with 100 mL each of saturated aqueous NaHCO3, water, and brine. The
organic layer was dried over MgSO4, filtered, concentrated, and purified by flash
chromatography (9:1 hexanes:acetone + 1% Et3N) to give 0.931 g (49.9%) of the desired
product as a white solid. ES-LC/MS shows [M+H]+ = 719. 13C NMR (100.6 MHz,
CDCl3) 5 219.1, 206.1, 169.5, 165.3, 135.3, 132.7, 129.0, 129.7, 128.3, 117.4, 100.7,
78.5, 76.6, 75.3, 74.2, 72.1, 69.2. 69.0. 64.5, 63.7. 50.6, 45.3, 44.8, 40.7, 38.3, 37.8, 31.7,
31.0, 21.1, 20.2, 19.5, 18.1, 16.5, 14.5, 14.0, 12.6, 12.2.
D. 2'-O-Benzoyl-6-O-allyl-3-descladinosyl-3-oxo-11 -O-methanesulfonyl- 15-
methyl-erythromycin A
2'-O- Benzoyl-6-O- Allyl-3-descladinosyl-3-oxo-15-methylerythromycin A (904
mg, 1.24 mmol, 1.00 eq) was dissolved in freshly distilled pyridine (4 mL) and cooled to
0 °C. Methanesulfonyl chloride (0.478 mL, 6.17 mmol, 5.00 eq) was added dropwise.
The reaction was allowed to come to ambient temperature and stirred overnight. The
mixture was diluted with 350 mL of EtOAe and quenched with 100 mL of saturated
aqueous NaHCO3. The layers were separated, and the organic phase was washed
successively with 100 mL each of water and brine. The organic phase was dried over
MgSO4, filtered, and concentrated. Flash chromatography over silica gel (4:1
hexanes:acetone + 1% Et3N) gave 741 mg (74.1%) of the desired compound as a white
solid. 13C NMR (100.6 MHz, CDCl3) d 203.0, 168.9, 165.0, 137.6, 133.1, 130.3, 129.8,
128.5, 114.4, 108.8, 102.2, 91.1, 84.4, 81.6, 78.8, 72.2, 69.2, 64.3, 63.9, 52.1, 46.6, 45.8,
40.7, 38.8, 38.2, 35.9, 31.8, 30.9, 29.7, 24.8, 21.0, 19.6, 18.2, 15.5, 15.4, 13.8, 13.5.
E. 2'-O-Benzoyl-6-O-allyl-3-descladinosyl-3-oxo-10,11-anhydro-15-methyl-
erythromycin A
2'-O- Benzoyl-6-O- allyl-3-descladinosyl-3-oxo-11-methanesulfonyl-15-methyl-
erythromycin A (705 mg, 0.870 mmol, 1.00 eq) was dissolved in acetone (3 mL), and
l, 8-diazabicyclo[5.4.0]undec-7-ene (0.651 mL, 4.35 mmol, 5.00 eq) was added dropwise.
The reaction was stirred at ambient temperature for 6 h and then concentrated. Flash
chromatography over silica gel (4:1 hexanes:acetone +1% Et3N) gave 486 mg (78.0%) of
the desired compound as a white solid. 13C NMR (100.6 MHz, CDC13) d 210.1, 208.4,
170.2, 165.2, 141.0, 140.2, 136.3, 132.7, 130.4, 129.8, 128.2, 115.5, 100.6, 81.0, 78.7,
77.2, 73.8, 72.0, 69.1, 64.6, 63.3, 51.0, 47.4, 40.8, 39.4, 36.2, 31.9, 31.3, 23.6, 21.2, 21.1,
21.0, 19.4, 14.1, 13.9, 13.7, 13.1.
Step 2: Formation of Imidazolide Intermediate (7) from Illustrative Scheme 3 and
Cyclization to Form Cyclic Carbamate of Compound (1 )/(10): Ra is -CH2CH=CH2, Rc is
benzoyl.
2'-O-Benzoyl-6-O-allyl-10, 11-anhydro-3-descladinosyl-3-oxo-15-methyl-
erythromycin A (227 mg, 0.317 mmol, 1.00 eq) was dissolved in 1.3 mL of freshly
distilled THF and cooled to -15°C under N2. Sodium hydride (25 mg of a 60% dispersion
in mineral oil, 0.634 mmol, 2.00 eq) was added, and the reaction was stirred for 15 min.
A solution of 1, 1-carbonyldiimidazole (140 mg, 0.866 mmol, 3.00 eq) in 1.3 mL of
freshly distilled THF was added dropwise. After stirring for 30 min, the reaction was
allowed to warm to ambient temperature over 1.5 h. The mixture was diluted with 100
mL of EtOAc and washed successively with 30 mL each of saturated aqueous NaHCO3,
water, and brine. The organic phase was dried over MgSO4, filtered, and concentrated to
give 275 mg of crude product (100%) which was dissolved in 2 mL of ACN and 0.2 mL
of anhydrous THF. Saturated aqueous ammonium hydroxide (2 mL) was added. The
reaction was sealed and stirred for 2 d. Volatiles were removed under reduced pressure,
and the residue was re-dissolved in 100 mL of EtOAc. The solution was washed
successively with 30 mL each of saturated aqueous NaHCO3, water, and brine. The
organic phase was dried over MgSO4, filtered, and concentrated. Rash chromatography
of the crude product (4:1 hexanes:acetone + 1% Et3N) ylelded 184 mg (76.5%) of the
desired product.
Example 19
Preparation of Compound of Formula (31: L is CO. T is NH, Ra is -CH2-(2-naphthyl)
Step 1: Alleviation of 6-OH to form compound (4) from Illustrative Scheme 2: R,
is -CH2-(2-naphthyl). Rc and Rc are H.
Following the procedures of Example 11, steps 1-3, except substituting (2-
naphthyl)mcthyl bromide for the allyl bromide of step 1, the compound is prepared.
Step 2: Protection of 2',4" hydroxyls to form intermediate compound (4) from
Illustrative Scheme 2: Ra is -CH2-(2-naphthyl), Rc and Rc are acetyl.
The compound from step 1 (2.0 g) is treated according to the procedure of
Example 16, step 1, except substituting acetic anhydride for the benzoic anhydride of that
example.
Step 3: Formation of Intermediate Compound (9) from Illustrative Scheme 2 and
Formation of Cyclic Carbamate of Compound (3) from Illustrative Scheme 2:
The compound of step 2 (500 mg) is treated with NaH and carbonyldiimidazole
and is treated with ammonia in acetonitrile according to the procedure of Example 18,
step 2 to afford the compound.
Preparation of Compound of Formula (I): Rc is acetyl. L is CO. T is NHL Ra is
-CH2CH-CH2
Step 1. Preparation of intermediate compound (4) from Illustrative Scheme 2: Ra
is -CH2CH=CH2, Rc and Rc are acetyl.
To a sample of the compound from Example 11, step 3 or an embodiment thereof
wherein Rd is propyl, butyl, benzyl, vinyl or 3-hydroxyburyl (405.2 g, 528 mmol) in
dichloromethane (20 mL) is added dimethylaminopyridine (0.488 g, 4 mmol) and acetic
anhydride (3.39 mL, 36 mmol), and the mixture is stirred at room temperature for 3
hours. The mixture is diluted with methylene chloride, then washed with 5% aqueous
sodium bicarbonate and brine and dried over Na2SO4- The residue is dried and
recrystallized from acetonitrile to give the compound.
Step 2: Dehydration at C-10,11 and derivation of C-12 to form intermediate
compound (9) from Illustrative Scheme 2: Ra is -CH2CH=CH2, Rc and Rc are acetyl.
To a sample of the compound from step 1 (85.8 g, 100 mmol) in dry THF (500
mL) cooled to -40°C and flushed with nitrogen is added sodium bis(trimethylsilyl)amide
(125 mL, 125 mmol) over 20 minutes, and the mixture is stirred at -40°C for 40 minutes.
To this mixture is added a solution of carbonyldiimidazole (3.65 g, 22.56 mmol) in 5:3
THF/DMF (800 mL) under nitrogen at -40°C over 30 minutes, and the mixture is stirred
at -20°C for 30 minutes. The mixture is stirred at room temperature for 27 hours, then
diluted with ethyl acetate. The mixture is washed with 5% sodium bicarbonate and brine,
dried over Na2SO4, and concentrated to give the compound (9), which is taken directly to
the next step.
Step 3: Formation of cyclic carbamate of compound (31 from Illustrative Scheme
2: R, is -CH2CH=CH2. Rc and Rc are acetyl.
The compound from step 2 (124 g) is dissolved in 9:1 acetonitrile/THF (1100
mL), ammonium hydroxide (28%, 200 mL) is added, and the mixture is stirred at room
temperature under nitrogen for 8 days. The solvent is removed, and the residue is
dissolved in ethyl acetate. This solution is washed with 5% sodium bicarbonate and
brine, dried over Na2SO4, and concentrated to give compound (3),
Step 4: Preparation of 3-OH form of compound (1): Ra is -CH2CH=CH2, Rc and
Rc are acetyl.
To a sample of the compound from step 3 (69.0 g, 78.2 mmol) suspended in
ethanol (200 mL) and diluted with water (400 mL) is added HC1 (0.972 N, 400 mL)
dropwise over 20 minutes. The mixture is stirred for 4 hours, and additional HC1 is
added (4 N, 100 mL) over 20 minutes. The mixture is stirred for 18 hours, cooled to 0"C,
then NaOH (4 N, 200 mL) is added over 30 minutes to approximately pH 9. The
intermediate compound is isolated by filtration.
Step 5: Preparation of compound (1): Ra is -CH2CH=CH2, Rc and Rc are acetyl.
L is CO. T is NH.
To a -10°C solution under nitrogen of N-chlorosuccinimide (2.37 g, 17.8 mmol) in
dichloromethane (80 mL) is added dimethylsulfide (1.52 mL, 20.8 mmol) over 5 minutes.
The resulting white slurry is stirred for 10 minutes at -10°C, a solution of the compound
from step 4 (8.10 g, 11.9 mmol) in dichloromethane (60 mL) is added and the reaction
mixture is stirred for 30 minutes at -10 to -5°C. Triethylamine (1.99 mL, 14.3 mmol) is
added dropwise over 10 minutes and the reaction mixture is stirred for 1 hour at 0°C. The
reaction mixture is extracted with dichloromethane. The organic phase is washed with
aqueous 5% sodium bicarbonate and brine, dried over sodium sulfate, and concentrated in
vacuo to give a white foam. Chromatography on silica gel (eluting with 50:50:0.5
acetone/hexanes/ammonium hydroxide) gives the compound.
Alternate preparation of compound of Formula (1): L is CO. T is NH. Ra is
-CH2CH=CH-(3-quinolyl)
Step 1: Preparation of compound of formula (1): Rb, is H. Rd is propyl. L is CO,
T is NH. Ra is -CH2CH=CH-(3-quinoyl).
Preparation A: Formula (11: R, , = H. R, is -CH;-CH=CH-(3-quinolyl)
2'-O- Benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-deoxy-3-oxo-15-
methylerythromycin A 11, 12-cyclic carbamate (40 mg, 0.0528 mmol, 1.0 eq),
tris(dibenzylideneacetone) dipalladium(O)-cbloroform adduct (14 mg, 0.014 mmol, 0.5
eq), tri-o-tolylphosphine (17 mg, 0.055 mmol, 1.0 eq), and 3-bromoquinoline (72 µL 0.53
mmol, 10 eq) were placed in a round-bottom flask which was flushed with N2. Degassed
acetonitrile (1 mL) and freshly distilled Et3N (0.015 ml, 0.11 mmol, 2.0 eq) were added.
The reaction was refluxed for 63 h. The mixture was returned to ambient temperature
and diluted with 40 mL of EtOAc. The solution was washed successively with 10 mL
each of saturated aqueous NaHCO3, water, and brine. The organic phase was dried over
MgSO4, filtered, and concentrated. Flash chromatography of the crude product (grathent
from 5:1 to 2:1 hexanes:acetone + 1% Et3N) ylelded 34 mg of the desired product.
Step 2: The above product (34 mg) was dissolved in 1 mL of methanol, sealed,
and refluxed at 80°C for 16 h. Volatiles were removed under reduced pressure. Flash
chromatography (1:1 hexanes:acetone + 1 % Et3N) gave the desired product as a light
yellow solid (2S mg, 61% over two steps). ES-LC/MS: [M+H]+ = 780.5. 13C-NMR
(CDC13, 100 MHz): d 217.44, 205.37, 169.48, 157.69, 149.71, 147.61, 132.51, 129.96,
129.56, 129.15, 129.05, 128.49, 128.05, 126.70, 102.90, 83.42, 78.71, 76.42, 75.91,
70.22, 69.53, 65.83, 64.31, 58.12, 50.81, 46.29, 46.12, 45.05, 40.18 (2 C), 39.05, 37.31,
31.64, 28.19, 21.15, 20.18, 19.43, 18.05, 14.38, 14.11, 13.76, 13.63 (2 C).
Preparation B: Formula (1) Rb, = H, Ra is -CH2-CH=CH-(3-(6-fluoroquinolyl)
This was prepared according to the method of Preparation A using 3-bromo-6-
fluoroquinoline in place of 3-bromoquinoline. ES-LC/MS: [M+H]+ = 798.5. 13C-NMR
(CDCl3, 100 MHz): d 217.49, 205.36, 169.54, 160.6 (JCF = 248Hz), 157.68, 149.05,
144.69, 131.84, 131.64 (JCF = 9 Hz), 130.28, 129.63, 129.31, 128.7 (JCF = 10 Hz), 119.20
(JCF = 27 Hz), 110.87 (JCF = 22 Hz), 102.94, 83.42, 78.77, 76.44, 75.91, 70.22, 69.55,
65.84, 64.24, 58.09, 50.83, 46.36, 46.06, 45.05, 40.18 (2 C) 39.04, 37.32, 31.63, 28.19,
21.16, 20.19, 19.46, 18.04, 14.37, 14.18, 13.76, 13.62 (2 C).
Preparation C: Formula (1): Rb = H, Ra is -CH2-CH=CH-(3-(6-chloroauinolyl)
This is prepared according to the method of Preparation A using 3-bromo-6-
chloroquinoline in place of 3-bromoquinoline. ES-LC/MS: [M+H]+ = 814.5. l3C-NMR
(CDC13, 100 MHz): d 217.48, 205.35, 169.55, 157.67, 149.90, 145.92, 132.42, 131.49,
130.80, 130.44, 129.92, 129.49.129.46. 128.71, 126.57, 102.94, 83.41, 78.78, 76.45,
75.91, 70.22, 69.54, 65.83, 64.23, 58.07, 50.83, 46.39, 45.99, 45.04, 40.17 (2 C), 39.03,
37.32, 31.62, 31.53, 28.18, 21.16, 20.17, 19.49, 18.04, 14.36, 14.21, 13.76, 13.61 (2 C).
Preparation D: Formula (1): Rb = H, Ra is -CH2-CH=CH-(4-isoquinolyl)
This was prepared according to the method of Preparation A using 4-
bromoisoquinoline in place of 3-bromoquinoline. ES-LC/MS: [M+H]+ = 781. 13C-NMR
(CDCl3, 100 MHz): d 217.19, 205.43, 169.75, 157.39, 152.07, 140.74, 133.61, 130.65,
130.44, 128.07, 127.72, 127.05, 126.89, 122.77, 102.85, 83.28, 78.74, 75.72, 70.22,
69.51, 65.88, 64.45, 58.10, 50.91, 46.07, 45.09, 40.18 (2 C) 38.99, 37.34, 31.48, 29.66,
28.28, 21.18, 20.39, 19.33, 14.53, 14.01, 13, 86, 13.66, 13.62.
Preparation E: Formula (1): Rb = H, Ra is -CH2-CH=CH-(3-pyridyl)
This was prepared according to the method of Preparation A using 3-
bromopyridine in place of 3-bromoquinoline. LC/MS: [M+H]+ = 731.13C-NMR (CDCl3,
100 MHz): d 217.39, 205.27, 169.50, 157.61, 148.81, 148.68, 132.63, 132.16, 129.65,
128.18, 123.46, 102.91, 83.36, 78.63, 76.35, 75.79, 70.20, 69.52, 65.83, 64.17, 58.06,
50.78, 46.28, 45.03, 40.16 (2 C), 38.96, 37.29. 31.64, 31.52, 28.19, 22.58, 21.14, 20.21,
19.42, 18.04, 1.35, 14.12, 14.05, 13.79, 13.61 (2 C).
Preparation F: Formula (1): Rb, = H, Ra is -CH2-CH=CH-(3-(6-methylquinolyl)
This was prepared according to the method of Preparation A using 3-bromo-6-
methylquinoline in place of 3-bromoquinoline. ES-LC/MS: [M+H]+ = 795. 13C-NMR
(CDC13, 100 MHz): d 217.37, 205.35, 169-47, 157.65, 148.82, 146.23, 136.45, 131.87,
131.37, 130.09, 129.51, 128.78, 128.22, 128.06, 126.86, 102.87, 83.40, 78.68, 75.91,
70.20, 69.47, 65.83, 64.33, 58.11, 50.81, 46.28, 45.04, 40.15 (2 C), 39.05, 37.31, 31.64,
28.24, 21.52, 21.14, 20.18, 19.45, 18.05, 14.38, 14.11, 13.77, 13.63 (2 C).
Preparation G: Formula (1): Rb = H. Ra is -CH2-CH=CH-(3-(6-aminoauinolyl)
This was prepared according to the method of Preparation A using 3-bromo-6-
aminoquinoline in place of 3-bromoquinoline. ES-LC/MS: [M+H]+ = 796.
Preparation H: Formula (1): Rb, = H, Ra is -CH2-CH=CH-(3-(5-isoxazol-3-yl),thienyl)
This is prepared according to the method of Preparation A, using 5-(isoxazol-3-
yl)-2-bromothiophene in place of 3-bromoquinoline.
Preparation I: Formula (1): Rb = H, Ra is -CH2-CH=CH-(6-quinolyl)
This is prepared according to the method of Preparation A, using 6-
bromoquinoline in place of 3-bromoquinoline.
Preparation J: Formula (1): Rb = H, Ra is -CH2-CH=CH-(3-quinoxal-6-yl)
This is prepared according to the method of Preparation A using 6-
bromoquinoxaline in place of 3-bromoquinoline.
Preparation K: Formula (IV Rb = H. Ra is -CH2-CH=CH-(5-(N-(2-pyridyl)-2-furamidyl)
This is prepared according to the method of Preparation A, using N-(2-pyridyl) 5-
bromo-2-furamide in place of 3-bromoquinoline.
Preparation AA: Formula (1): Rb = F, Ra is -CH2-CH=CH-(3-quinolyl)
This was prepared according to the method of Preparation A using 2'-O- benzoyl-
6-O-allyl-11-amino-3-descladinosyl-11-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- berizoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate. LC/MS: [M+H]+ =
798.6. 19F-NMR (CDC13, 376 MHz): d -163.93. 13C-NMR (CDC13, 100 MHz): d 217.97,
204.28 (JCf = 27 Hz), 165.62 (Jcf = 23 Hz), 157.18, 149.71, 147.70, 132.65, 130.25,
129.53, 129.22, 129.12, 129.06, 128.15, 128.08, 126.78, 104.10, 98.02(JCF = 206 Hz),
83.40, 79.59, 79.37, 77.57, 70.41, 69.74, 65.85, 64.36, 58.11, 44.23, 40.83 (Jcf = 1.5 Hz),
40.25 (2 C), 39.04, 37.45, 31.37, 28.16, 25.30 (Jcf - 22 Hz), 21.19, 20.86, 19.54, 17.67,
15.46 (Jcf = 1.7 Hz)„ 13.82, 13.80, 13.29.
Preparation BB: Formula (1). Rb = F, Ra is -CH2-CH=CH-(3-(6-fluoroquinolyl)
This is prepared according to the method of Preparation B using 2'-O- benzoyl-6-
O-allyl-l l-arnino-3-descladinosyl-l l-deoxy-3-oxo-2-fiuoro-l 5-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-1 1-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation CC: Formula (1): Rb = F, Ra is -CH2-CH=CH-(3-(6-chloroquinolyl)
This is prepared according to the method of Preparation C using 2'-O- benzoyl-6-
O-allyl-l l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2-O-benzoyl-6-O-allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation DP: Formula (1) Rb = F, Ra is -CH2-CH=CH-(4-isoquinolyl)
This is prepared according to the method of Preparation D using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-l5-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythxomycin A 11, 12-cyclic carbamate.
Preparation EE: Formula (1) Rb = F. Ra, is -CH2-CH=CH-(3-pyridyl)
This is prepared according to the method of Preparation E using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fiuoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylcrythromycin A 11, 12-cyclic carbamate.
Preparation FF: Formula (1): Rb= F, Ra is -CH2-CH=CH-(3-(6-methylquinolyl)
This is prepared according to the method of Preparation F using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2, -O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation GG: Formula (1) Rb, = F, Ra is -CH2-CH=CH-(3-(6-aminoquinolyl)
This is prepared according to the method of Preparation G using 2'-O- benzoyl-6-
O-allyl-l l-amino-3-descladinosyl-11-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation HH: Formula (1): Rb = F, Ra is -CH2-CH=CH-(3-(5-isoxazol-3-yl)thienyl)
This is prepared according to the method of Preparation H using 2'-O- benzoyl-6-
O-allyl-11-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A

11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation II: Formula (1): Rb. = F, Ra is -CH2-CH=CH-(6-quinolyl)
This is prepared according to the method of Preparation. I using 2'-O- benzoyl-6-O- allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fiuoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O-benzoyl-6-O-allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation JJ: Formula (1): Rh = F. Ra is -CH2-CH=CH-(3-quinoxal-6-yl)
This is prepared according to the method of Preparation J using 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A. 11, 12-cyclic carbamate.
Preparation KK: Formula (1): Rb, = F, Ra is -CH2-CH=CH-(5-(N-(2-pyridyl)-2-
furamidyl)
This is prepared according to the method of Preparation K using 2'-O- benzoyl-6-
O-allyl-11-amino-3-descladinosyl-11-deoxy-3-oxo-2-fiuoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11 -
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Using the procedures described in the preceding examples and schemes and
methods known in the synthetic organic chemistry art, the cyclic carbamate compounds of
Formula (1) wherein L is CO and T is NH can be prepared. These compounds having the
Ra substituent are described below:
Example 22
Preparation of compound of formula (1): L is CO, T is N(CH3), Ra is -CH, CH=CH2,
Step 1: Preparation of Compound (10) from Illustrative Scheme 3: Rf is methyl,
Ra is -CH2CH=CH2, Rc is benzoyl.
Replacing the ammonium hydroxide of Example 18 with methylamine, the above
compound is formed.
Other Embodiments: Using the above procedures, compounds of formulas (l)-(3)
can be formed wherein L is CO, T is: -N(CH3); -NCH2CH2N(CH3)2; -N(CH2CH=CH2);
-N(CH2CH=CH-(3-quinolyl)); or -N(NH2); and R, is: -CH2CH=CH-(3-quinolyl);
-CH2CH-CH2; -CH2CH2CH2-(3-quinolyl); -CH2CH=CH-naphthyl; -CH2CH=CH-(8-
chloro-3-quinolyl);-CH2CH=CH-(4-chloro-2-trifluoromethyl-6-quinolyl);-CH2CH=CH-

(2-fluorenyl);-CH2CH=CH-(3-(2-furanyl)-6-quinolyl);-CH2CH=CH-(9-fluorenone-2-yl);
-CH2CH=CH-(6-benzoyl-2-naphthyl);-CH2CH=CH-(7-methoxy-2-naphthyl);
-CH2CH=CH-(3-phenyl-6-quinolyl);-CH2CH-CH-(3-(2-pyridyl)-6-quinolyl);
-CH2CH=CH-(3-(2-thiophenyl)-6-quinolyl);-CH2CH=CH-(4-methylnaphthyl);
-CH2GH=CH-(6-ß-D-galactopyranosyl-2-naphthyl);-CH2CH=CH-(7-quinolyl);
-CH2CH=CH-(4-fluoronaphthyl);-CH2CH=CH-(3-biphenyl);-CH2CH=CH-(5-
nitronaphthyl);-CH2CH=CH-(4-pyrrolylphenyl);-CH2CH=CH-(6-methoxy-2-naphthyl);
-CH2CH=CH-(3, 5-dichlorophenyl);-CH2-(3-iodophenyl);-CH2-(3-(2-furanyl)phenyl);
-CH2CH=CH-(6-hydroxy-2-naphthyl);-CH2CH=CH-(6-(2-bromoethoxy)-2-naphthyl);
-CH2CH=CH-(6-(2-(tetrazolyl)ethoxy-2-naphthyl);-CH2CH=CH-naphthyl;
-CH2CH=CH-(5-(3-isoxazolyl)-2-thiophenyl);-CH2CH=CH-(l,3-dimethyl-2, 4-dioxo-5-
pyrimidinyl); and -CH2CH==CH-(5-(2-pylidyl)aminocarbonyl-2-furanyl).
Further, following the procedures of Example 21, except substituting the reagent
below for the 3-bromoquinoline of Example 21, additional compounds are prepared.
These are compounds of Formula (1) wherein L is CO and T is O having the Ra
substituent as described below:
Conversion at -ORa
A. allyl ? -CH2CHO
The compound from Example 18 (14.0 g) is dissolved in CH2C12 (200 mL) and
the solution is cooled to -78°C under a nitrogen atmosphere. Ozone is then bubbled
through the solution until a blue color persisted. The reaction is then purged with N2 until
colorless and dimethylsulfide (14 mL) is added, and the reaction mixture is warmed to
0°C. After stirring for 90 min, the reaction mixture is concentrated under reduced
pressure to give a light-yellow foam. This material is dissolved in THF (300 mL) and
treated with triphenylphosphine (8 g) at reflux for 6 hours, then the reaction mixture is
concentrated under reduced pressure. Chromatography (1:1 acetone/hexanes to 3:1
acetone/hexanes with 0.5% TEA) gave the product.
B. -CH2CHO ? -CH2CH2NHCH2Phenyl
The compound from Example 23 A (120 mg, 0.187 mmol) and benzylamine (40
µL, 0.366 mmol, 2 equiv) are dissolved in 3 mL of dry dichloromethane. Molecular
sieves (4A) are added and the reaction is stirred overnight The reaction is then filtered
and concentrated under reduced pressure. The resulting imine is dissolved in MeOH (5
mL), a catalytic amount of 10% Pd on carbon is added, and the reaction is stirred rapidly
under 1 atm of H2 pressure for 20 hours. The mixture is then filtered through a Celite™
pad, and the solution concentrated under reduced pressure. Chromatography (SiO2, 5%
MeOH/dichloromethane with 0.2% NH4OH) gives the desired material (84 mg) as a
white solid.
C. -CH2CHO ? -CH2CH2NHCH2CH2Phenyl
This compound is prepared from the compound of Example 23A (108 mg, 0.169
mmol) and phenethylamine (42 µL, 0.334 mmol, 2 equiv) using the procedure described
for Example 23B. Chromatography (SiO2, 5% MeOH/dichloromethane with 0.5%
NH4OH) gives the desired material.
D. -CH2CHO ? -CH2CH2NHCH2CH2CH2Phenyl
This compound is prepared from the compound of Example 23A (100 mg, 0.156
mmol) and 3-phenyl-1-propylamine (40 µL, 0.282 mmol, 1.8 equiv) using the procedure
described for Example 23B. Chromatography (SiO2, 5% MeOH/dichloromethane with
0.5% NH4OH) gives the desired material.
E- -CH2CHO ? -CH2CH2NHCH2CH2CH2CH2Phgnyl
This compound is prepared from the compound of Example 23A (170 mg, 0.266
mmol) and 4-phenyl-1-butylamine (68 µL, 0.431 mmol, 1.6 equiv) using the procedure
described for Example 23B. Chromatography (SiO2, 5% MeOH/dichloromethane with
0.2% NH4OH) gives the desired material.
F. -CH2CHO ? -CH2CH2NHCH2CH2CH2-(3-quinolyl)
The compound from Example 23A (135 mg, 0.211 mmol) and 3-(3-quinolyl)-l-
propylamine (70 mg, 0.376 mmol, 1.8 equiv) are dissolved in 4 mL of dry
dichloromethane. Molecular sieves (4Å), are added and the reaction is stirred overnight.
The reaction is then filtered and concentrated under reduced pressure. The resulting
imine is dissolved in MeOH (5 mL) and treated with NaCNBH3 (about 100 mg) and
enough AcOH to turn bromocresol green indicator from blue to yellow. After stirring for
4 hours, the reaction mixture is poured into saturated NaHCO3 solution and extracted into
dichloromethane. The organic portion is washed with saturated NaHCO3, H2O and brine,
dried (Na2SO4) and concentrated under reduced pressure. Chromatography (SiO2, 5%
MeOH/dichloromethane with 0.5% NH4OH to 10% MeOH/dichloromethane with 1%
NH4OH) gives the desired material.
G. -CH2CHO? -CH2CH2NHCH2(3-quinolyl)
The title compound is prepared from the compound of Example 23 A (150 mg,
0.234 mmol) and 3-(aminomethyl)quinoline (100 mg, 0.633 mmol, 2.7 equiv) using the
procedure described for Example 23F. Chromatography (SiO2, 5%
MeOH/dichloromethane with 0.5% NH4OH) gives the desired material
The 3-(aminomethyl)quinoline reagent is prepared by methods known in the art.
Other embodiments of the formulas (l)-(3) wherein Rb, is H, Rc is H, L is -CO-, T
is -NH-, and Rd is propyl, butyl, benzyl, vinyl, or 3-hydroxy butyl are those wherein Ra is
converted from -CH2CHO to: -CH2CH2NHCH2(6-quinolyl); -CH2CH=NO(phenyl);
-CH2CH-NOCH2(phenyl); -CH2CH=NOCH2(4-NO2-phenyl); -CH2CH=NOCH2(4-
quinolyl); -CH2CH=NOCH2(2-quinolyl); -CH2CH-=NOCH2(3-quinolyl);
-CH2CH=NOCH2(6-quinolyl); -CH2CH=NOCHz( 1 -naphthyl); -CH2CH=NOCH2(2-
naphthyl); -CH2CH2NHOCH2(phenyl); -CH2CH2NHOCH2(4-NO2-phenyl); -CH2C(O)-
phenyl; -CH2C(O)-(4-F-phenyl); -CH2CH=NNHC(O)phenyl; or -CH2CH(OH)-phenyl.
H. -CH2CH=CH-(3-quinolyl) ? -CH2CH2CH2(3-quinolyl)
A mixture of the compound from Example 18 where Ra is -CH2CH=CH-(3-
quinolyl) (230 mg) and 10% Pd/C (50 mg) in 30 mL of methanol and 15 mL of ethyl
acetate is flushed with nitrogen and stirred under 1 atm of hydrogen at room temperature
for 22 hours. The mixture is filtered, and the filtrate is concentrated under reduced
pressure. Chromatography on silica gel (5% MeOH/dichloromethane with 0.5% NH4OH)
gives the desired material.
I. -CH2CH=CH-(3-quinolyl) ? -CH2(2-(3-quinolyl)-cyclopropyl)
To a solution of diazomethane (0.64 M, 3.12 mL, 2.00 mmol) in ether is added a
solution of the compound from Example 18 wherein Ra is -CH2CH=CH-(3-quinolyl) (153
mg, 0.200 mmol) in dichloromethane (5.0 mL) at 0'C under nitrogen. A small amount (2
mg) of palladium acetate is added, and the mixture is stirred for 20 minutes. Another
portion of diazomethane (3 mL) is added, and the mixture is stirred for another hour. The
solvents are evaporated, and the residue is purified by chromatography on silica gel (5%
MeOH/dichloromethane with 0.5% NH4OH) to give the title compound as a white solid.
Example 24
Conversions at Rc
A. -H ? propanoyl (Ra is -CH2CH=CH-(3-quinolyl))
To a solution of the compound from Example 18 converted at Ra, wherein Ra is
-CH2CH=CH(3-quinolyl), (152 mg) in dichloromethane is added propionic anhydride (52
µL) and triethylarnine (56 µL), and the mixture is stirred for 24 hours at room
temperature. The mixture is diluted with ethyl acetate, and this is washed with 5%
NaHCO3 solution and brine, dried (Na2SO4) and concentrated under reduced pressure.
The residue is chromatographed on silica gel (1:1 acetone/hexanes) to give the title
compound as a white foam.
B. -H - ethylsuccinoyl (Ra is -CH2CH=CH-(3-quinolyl))
To a solution of the compound from Example 18 converted at Ra, wherein Ra is
-CH2CH=CH-(3-quinolyl) (153 mg, 0.200 mmol) in dichloromethane (10 mL) at 0°C is
added ethyl succinyl chloride (29 µL) and triethylamine (56 µL), and the mixture is stirred
for 24 hours at room temperature. The mixture is diluted with ethyl acetate, and this is
washed with 5% NaHCO3 solution and brine, dried (Na2SO4) and concentrated under
reduced pressure. The residue is chromatographed on silica gel (1:1 acetone/hexanes) to
give the title compound as a white foam.
Example 25
Preparation of Compound of Formula (1): L is CO, T is NH. Ra is -CH2C =C-H, Rc.
and Rc are H
Step 1: Preparation of intermediate of compound (4): position 9 is N-Q-(1-
isopropoxycyclohexyl), Ra is -CH2C =C-H,. Rc and Rc are trimethylsilyl.
To a solution under nitrogen of 2',4"-bis-O- trimethylsilylerythromycin A 9-[O-(1-
isopropoxycyclohexyl)]oxime (100 g, 96.9 mmol, prepared according to the method of
U.S. Patent No. 4, 990, 602) in THF (200 mL) is added anhydrous DMSO (200 mL) and
the mixture is cooled to 0°C. To this solution stirred under a N2 atmosphere is added
propargyl bromide (27 mL, 240 mmol, 80 wt. % in toluene), followed by a solution of dry
KOH (13.6 g, 240 mmol) in anhydrous DMSO (300 mL) over 25 minutes, and the
mixture is stirred vigorously for 1 hour at 0°C Additional KOH (10.9 g, 190 rnmol) and
propargyl bromide (21 mL, 190 mmol) is added, and the mixture is stirred at 0°C under
N2 for 1.5 hours. This addition of KOH and propargyl bromide is repeated 3 more times
at 1.5 hour intervals. The mixture is then extracted with ethyl acetate, and the organic
phases are washed with water and brine and dried (MgSO4). Removal of the solvent
under vacuum gives the crude product, which is taken directly to the next step.
Step 2: Conversion of -N-Q-(1-isopropoxycyclohexyl) at Position 9 to -NOH in
intermediate of compound (4): Ra is, -CH2C =C-H.
To the compound from Step 1 (108 g) in CH3CN (300 mL) is added water (150
mL) and acetic acid (glacial, 200 mL), and the mixture is stirred at room temperature for
about 20 hours. The solvent is then removed under vacuum at 40°C, and the residue is
taken up in EtOAc and washed successively with 5% Na2CO3 and brine. The organic
phase is then dried over MgSO4, filtered and concentrated to give the compound as a
brown foam, which is taken directly to the next step.
Step 3: Conversion of-NOH at Position 9 to ==O to form intermediate compound
(41: Ra is-CH2C =C-H.
The compound from Step 2 (74 g) is dissolved in ethanol (550 mL) and diluted
with water (550 mL). To this solution is added sodium nitrite (33 g, 0.48 mol), and the
reaction mixture is stirred at room temperature for 15 minutes. Next is added 4M HC1
(125 mL, 0.48 mol) at ambient temperature over 15 minutes, the mixture is heated to
70°C for two hours, then cooled to room temperature. The mixture is extracted with ethyl
acetate, and the organic phase is washed with 5% Na2CO3 and brine, then dried over
MgSO4, filtered and concentrated. The crude product is purified by chromatography on
silica gel, eluting with 1% methanol/dichloromethane containing 0.5% ammonium
hydroxide. The compound is crystallized from acetonitrile to give the compound.
Step 4: Protection of 2' and 4" hydroxyl groups to form intermediate compound
(4) from Illustrative Scheme 2: Rc and Rc are acetyl, Ra is -CH2C =C-H.
To a solution of 19 grams (246 mrnol) the compound from Step 3 in anhydrous
dichloromethane (100 mL) is added 4-dimethylaminopyridine (105 mg) and triethylamine
(7.16 mL, 52 mmol). The mixture is cooled to about 15°C in a cold water bath, and acetic
anhydride (5.5 mL, 59 mmol) is added over 5 minutes, After stirring at 15°C for 5
minutes, the cold water bath is removed, and the reaction is stirred at ambient temperature
for 4 hours. The mixture is diluted with ethyl acetate and washed successively with 5%
aqueous sodium carbonate (twice), water (twice) and brine. The organic extracts are

dried over magnesium sulfate, filtered and concentrated in vacuo. Drylng to constant
weight with high vacuum provided the compound.
Step 5: Dehydration at position 10. 11 and Derivation at Position 12 to form
intermediate compound (9) from Illustrative Scheme 2: Rc and Rc are acetyl, Ra is
-CH2C =C-H.
To a 0°C solution of the compound from Step 4 (21 g, 24.5 mmol) in THF (128
mL) and dimethyl sulfoxide (48mL) is added l, 1-carbonyldiimidazole (14.3 g, 88.3
mmol). After stirring for 5 minutes, sodium hydride (60% dispersion in mineral oil, 1.3
g, 32.5 mmol) is added portionwise over 1 hour under a nitrogen atmosphere. After
complete addition, the cooling bath is removed, and the mixture is stirred at ambient
temperature for 3.5 hours. The reaction is recooled to 0°C, diluted with ethyl acetate
(-400 mL), and quenched with 5% aqueous sodium bicarbonate (50 mL). The organic
layers are washed successively with water and brine, then dried over magnesium sulfate.
The solution is filtered and the filtrate is concentrated in vacuo and dried to constant
weight to afford the compound which is taken directly to the next step.
Step 6: Form cyclic carbamate of compound (3) from Illustrative Scheme 2: Rc
and Rc are acetyl, Ra is -CH2C =C-H.
A pressure vessel containing the compound from Step 5 (23 g, 24 mmol) in
acetonitrile (250 mL) is cooled to -78°C. An equal volume of liquid ammonia (250 mL)
is condensed into the reaction vessel which is then sealed and allowed to warm to
ambient temperature with stirring. After 20 hours the reaction is recooled to -78°C, the
pressure vessel is opened and the reaction was allowed to warm to ambient temperature
with stirring. When all the liquid ammonia had evaporated, the acetonitrile is removed in
vacuo, and the residue is dried to constant weight to provide the compound.
Step 7: Remove Position 3 Cladinose moiety to form compound (1) having a
position 3 hydroxyl group: Rc is acetyl. Ra is -CH2C=C-H.
To a 0°C suspension of the compound from Step 6 (21 g) in 1:1 ethanol/water
(200 mL) is added 4 M hydrochloric acid (125 mL) over 10 minutes. After removing the

cooling bath, the reaction solution is stirred at ambient temperature for 26 hours. The
mixture is diluted with water, cooled to 0°C and made basic to pH 10 with 2N sodium
hydroxide. The mixture is then extracted with ethyl acetate (400 mL), and the organic
layers are washed with brine. The organic extracts are dried over magnesium sulfate,
filtered, and concentrated in vacuo. Drying to constant weight provided 18 g of the crude
product which is crystallized from ethyl acetate/hexanes to give the pure compound.
Step 8: Oxidation of Position 3 hydroxyl to carbonyl of compound (1). Rc acetyl.
Ra is-CH2C =C-H.
To a -10°C solution of N-chlorosuccinimide (2.3 g, 0.017 moles) in
dichloromethane (100 mL) is added methyl sulfide (1.47 mL, 0.021 moles) over 5
minutes. The reaction is stirred at -10°C for 10 minutes. A solution of the compound
from Step 7 (8.3 g, 0.012 m) in dichloromethane (100 mL) is then added over 30 minutes,
and the mixture is stirred for 25 minutes at -10°C. Triethylamine (1.6 mL, 0.021 mol) is
added over 5 minutes, and the reaction is stirred at -10°C for 50 minutes. The reaction is
then quenched with 5% aqueous sodium bicarbonate (50 mL), and extracted with
dichloromethane (300 mL). The organic layers are washed with 5% aqueous sodium
bicarbonate followed by brine, dried over magnesium sulfate, filtered, and concentrated in
vacuo. The crude product is purified on silica gel with column chromatography eluting
sequentially with 30% acetone/hexanes followed by 50% acetone/hexanes to provide the
compound.
Step 9: Deprotection to form compound of Formula (1): L is CO. T is NH, Ra is
-CH2C=C-H,Rc .is H.
A sample (72 mg) of the compound from Step 8 is dissolved in methanol (8 mL)
and stirred at ambient temperature for 18 hours. After concentrating under vacuum and
drylng to constant weight under high vacuum 65 mg of the pure title compound is
obtained.
Optional Step: Conversion of Ra from -CH2C=C-(6-rnethoxy-2-naphthyl
bromonaphthalene) to -CH2C =C -Br to form compound (1): Ra is -CH2C =C -Br, Rc is
cetyl.
To a solution under nitrogen of the compound of Example 25, Step 8 (100 mg) in
acetone (1 mL) is added acetic acid (8.4 µL) at ambient temperature. A second solution
containing N-bromosuccinimide (39 mg) and silver nitrate (2.5 mg) in 1 mL of acetone is
prepared and then stirred at room temperature under nitrogen for ten minutes and is
cooled to 0°C. The first solution is then added to the second solution in one portion, the
cooling bath is removed, and the resulting reaction mixture stirred at room temperature
under nitrogen for 2 hours. The reaction is then diluted with ethyl acetate, saturated
aqueous sodium bicarbonate is added, and the mixture is stirred at room temperature
overnight. The organic phase is separated, washed with brine and dried (MgSO4). The
solvent is removed, and the residue is purified by chromatography on silica gel, eluting
with 40% acetone/hexanes to give the compound. The Rc group can be deprotected with
methanol.
Example 26
Preparation of Compound of Formula (1): L is CO, T is NH, Ra is specified below, Rc is
H, Rb is H, Rd is propyl
I. Starting Material: Preparation of Compound of Formula (1): Rb = H, Ra is -O-
propargyl
Step 1: A solution of 2',4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-
(l-isopropoxycyclohexyl)]oxime (100 mg) in 0.1 mL of tetrahydrofuran, 0.1 mL of ether,
and 0.1 mL of DMSO was cooled to 10°C and treated with 0.028 mL of 3-bromo-l-
(trimethylsilyl)-l-propyne under inert atmosphere. A mixture of methylsulfoxide (0.19
mL) and 1.0 M potassium tert-butoxide in tetrahydrofuran (0.38 mL) was added at a rate
of 2.0 molar equivalents of base per hour. Additional equivalents (0.014 mL) of the
TMS-propargyl bromide were added after 0.5 and 1 hours. The reaction was monitored
by thin-layer chromatography (silica gel, 10:1 toluene/acetone), and was judged complete
after addition of 2.3 molar equivalents of base. The reaction was diluted with 100 mL of
ethyl acetate and 30 mL of saturated NaHCO3, and washed sequentially with saturated
NaHCO3, water, and brine. The organic phase was dried with MgSO4, filtered, and
evaporated. The crude product was chromatographed on silica gel (40:1 hexanes/acetone
+ 1% Et3N) to yleld partially purified 6-O- (3-trimethylsilyl)propargyl-2, , 4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime.
Step 2: A solution of the impure 6-O- (3-trimethylsilyl)propargyl-2, , 4"-bis-O- trimethylsilyl-15-methylerythromycin A 9-[O-(l-isopropoxycyclohexyl)]oxime from
above (0.88 g) in 4.4 mL of acetonitrile is treated with 2.2 mL of water and 2.5 mL of
acetic acid, and stirred for 24 hours at ambient temperature. The mixture is concentrated
after addition of 2-propanol, then repeatedly after addition of toluene. This material is
stirred with potassium carbonate and methanol (6 mL) for 2.5 hours. The mixture is
diluted with ethyl acetate (200 mL), and washed sequentially with saturated NaHCO3,
water, and brine. The organic phase is dried with MgSO4, filtered, and evaporated to
yleld the product.
Step 3: A solution of the product from (iii) and sodium hydrosulfite (0.59 g) in 7
mL of 1:1 ethanol/water is placed under inert atmosphere. Formic acid (0.096 mL) is
added dropwise, and the mixture is stirred at 80°C for 5 hours. After cooling to ambient
temperature, the reaction is adjusted to pH 10 with 6 N NaOH and extracted three times
with 150-mL portions of ethyl acetate. The organic extracts are combined and washed
sequentially with saturated NaHCO3, water, and brine. The organic phase is dried with
MgSO4, filtered, and evaporated to yleld 6-O- propargyl-15-methylerythromycin A
suitable for further conversion. Pure material can be prepared by chromatography on
silica gel.
Step 4: A mixture of 6-O- propargyl-15-methylerythromycin A (0.40 g) and 6 ml
of 0.6 N HC1 is stirred at ambient temperature for 17 hours. The pH is adjusted to 9 by
addition of 6 N NaOH, and 150 mL of ethyl acetate is added. The organic extracts are
washed sequentially with saturated NaHCO3, water, and brine, then dried over MgSO4,
filtered, and evaporated to provide further product. The crude product is
chromatographed on silica gel to give pure 6-O- propargyl-3-descladinosyl-15-
methylerythromycin A.
Step 5: A solution of 6-O- propargyl-3-descladinosyl-15-methylerythromycin A
(0.16 g) and benzoic anhydride (0.12 g) in 13 mL of ethyl acetate is stirred for 17 h, then
washed sequentially with saturated NaHCO3, water, and brine. The solution is dried over
MgSO4, filtered, and evaporated- The crude product is chromatographed on silica gel to
yleld 2'-O- benzoyl-6-O- propargyl-3-descladinosyl-15-methylerythromycin A.
Step 6: N-Chlorosuccinimide (0.510 g, 3.82 mmol, 1.50 eq) is dissolved in 13 mL
of anhydrous CH2C12 and cooled to -10 °C under N2. Methyl sulfide (0.328 mL, 4.46
mmol, 1.75 eq) is added, and the reaction is stirred for 15 min. A solution of 2'-O- benzoyl-6-O- propargyl-3-descladinosyl-15-methylerythromycin A (1.87 g, 2.55 mmol,
1.00 eq) in. 13 mL of anhydrous CH2Cl2 is added dropwise. After 30 min, freshly distilled
Et3N (0.355 mL, 2.55 mmol, 1.00 eq) is added, and the reaction is brought up to 0 °C
over 30 min. The reaction mixture is diluted with 400 mL EtOAc and washed
successively with 100 mL each of saturated aqueous NaHCO3, water, and brine. The
organic layer is dried over MgSO4, filtered, concentrated, and purified by
chromatography.
Step 7: 2, -O- Benzoyl-6-O- propargyl-3-descladinosyl-3-oxo-15-
methylerythromycin A (904 mg) is dissolved in freshly distilled pyridine (4 mL) and
cooled to 0°C. Methanesulfonyl chloride (0.478 mL, 6.17 mmol, 5.00 eq) is added
dropwise. The reaction is allowed to come to ambient temperature and stirred overnight.
The mixture is diluted with 350 mL of EtOAc and quenched with 100 mL of saturated
aqueous NaHCO3,The layers are separated, and the organic phase is washed
successively with 100 mL each of water and brine. The organic phase is dried over
MgSO4, filtered, and concentrated. Flash chromatography over silica gel ylelds the
product.
Step 8: 2'-O- Benzoyl-6-O- propargyl-3-descladinosyl-3-oxo-11-methanesulfonyl-
15-methyl-erythromycin A (705 mg) is dissolved in acetone (3 mL), and 1, 8-
dia2abicyclo[5.4.0]-undec-7-ene (0.651 mL, 4.35 mmol, 5.00 eq) is added dropwise. The
reaction is stirred at ambient temperature for 6 h and then concentrated. Flash
chromatography over silica gel ylelds the product.
Step 9: 2'-O-Benzoyl-6-O-propargyl-10, 11-anhydro-3-descladinosyl-3-oxo-15-
methylerythromycin A (227 mg) is dissolved in 1.3 mL of freshly distilled THF and
cooled to -15 °C under N2. Sodium hydride (25 mg of a 60% dispersion in mineral oil,
0.634 mmol, 2.00 eq) is added, and the reaction was stirred for 15 min, A solution of 1, 1-
carbonyldiimidazole (140 mg) in 1.3 mL of freshly distilled THF is added dropwise.
After stirring for 30 min, the reaction is allowed to warm to ambient temperature over 1.5
h. The mixture is diluted with 100 mL of EtOAc and washed successively with 30 mL
each of saturated aqueous NaHCO3, water, and brine. The organic phase is dried over
MgSO4, filtered, and concentrated, then the residue is dissolved in 2 mL of ACN and 0.2
mL of anhydrous THF. Saturated aqueous ammonium hydroxide (2 mL) is added. The
reaction is sealed and stirred for 2 days. Volatiles are removed under reduced pressure,
and the residue is redissolved in 100 mL of EtOAc. The solution is washed successively with 30 mL each of saturated aqueous NaHCO3, water, and brine. The organic phase is
dried over MgSO4, filtered, and concentrated. Flash chromatography ylelds the cyclic
carbamate product.
II. Preparation of Compounds using Compounds of I
Preparation A: Formula (1): Rb = H, Ra is -CH2-CC-(3-guinolyl)
Step 1: 2'-O- Benzoyl-6-O- propargyl-11 -amino-3-descladinosyl-11 -deoxy-3-oxo-
15-methylerythromycin A 11, 12-cyclic carbamate (40 mg), tris(dibenzylideneacetone)
dipalladium(O)-chloroform adduct (14 mg), tri-O-tolylphosphine (17 mg), copper iodide,
and 3-bromoquinoline (72 µl, 0.53 mmol, 10 eq) are placed in a round-bottom flask
which is flushed with N2- Degassed acetonitrile (1 mL) and freshly distilled Et3N (0.015
ml, 0.11 mmol, 2.0 eq) are added. The reaction is refluxed for 63 h. The mixture is
returned to ambient temperature and diluted with 40 mL of EtOAc. The solution is
washed successively with 10 mL each of saturated aqueous NaHCO3, water, and brine.
The organic phase is dried over MgSO4, filtered, and concentrated. Flash
chromatography ylelds the desired product.
Step 2: The above product is dissolved in 1 mL of methanol, sealed, and refluxed
at 80 °C for 16 h. Volatiles are removed under reduced pressure. Flash chromatography
ylelds the desired product.
Preparation B: Formula (1): Rb = H, Ra, is -CH2CC-(3-(6-fluorequinolyl)
This is prepared according to the method of Preparation A, using 3-bromo-6-
fiuoroquinoline in place of 3-bromoquinoline.
Preparation C: Formula (1): Rb - H, Ra, is -CH2-CC-(3-(6-chloroquinolyl)
This is prepared according to the method of Preparation A, using 3-bromo-6-
chloroquinoline in place of 3-bromoquinoline.
Preparation D: Formula (1): Rb, = H, Ra is -CH2-CC-(4-isoquinolyl)
This is prepared according to the method of Preparation A, using 4-
bromoisoquinoline in place of 3-bromoquinoline.
Preparation E: Formula (1): Rb = H, Ra, is -CH2-CC-(3-pyrridyl)
This is prepared according to the method of Preparation A, using 3-pyridine in
place of 3-bromoquinoline.
Preparation F: Formula (1): Rb, = H, Ra is -CH2-CC-(3-(6-methylquinolyl)
This is prepared according to the method of Preparation A, using 3-bromo-6-
methylquinoline in place of 3-bromoquinoline.
Preparation G: Formula (1): Rb = H, Ra is -CH2-CC-(3-(6-aminoquinolyl)
This is prepared according to the method of Preparation A, using 3-bromo-6-
aminoquinoline in place of 3-bromoquinoline.

Preparation H: Formula (1): Rb = H, Ra is -CH2CC-(3-(5-isoxazol-3-yl)thienyl)
This is prepared according to the method of Preparation A, using 5-(isoxazol-3-
yl)-2-bromothiophene in place of 3-bromoquinoline.
Preparation I: Formula (1): Rb = H, Ra is -CH2CC-(6-quinolyl)
This is prepared according to the method of Preparation A, using 6-
bromoquinoline in place of 3-bromoquinoline.
Preparation J: Formula (1): Rb = H, Ra is -CH2-CC-(3-quinoxal-6-yl)
This is prepared according to the method of Preparation A using 6-
bromoquinoxaline in place of 3-bromoquinoline.
Preparation K: Formula (1): Rb = H, Ra is -CH2-CC-(5-(N-(2-Pyridyl)-2-
furamidyl)
This is prepared according to the method of Preparation A, using N-(2-pyridyl) 5-
bromo-2-furamide in place of 3-bromoquinoline.
Preparation AA: Formula (1): Rb = F. R, is -CH2-CC-(3-quinolyl)
This was prepared according to the method of Preparation A using 2'-O- benzoyl-
6-O-allyl-l l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'- O-benzoyl-6-O-allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation BB: Formula (1): Rb = F, Ra is -CH2-CC-(3-(6-fluoroquinolyl)
This is prepared according to the method of Preparation B using 2'-O- benzoyl-6-
O-allyl-11-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythxomycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation CC: Formula (1). Rb = F, Ra is -CH2-CC-(3-(6-chloroauinolyl)
This is prepared according to the method of Preparation C using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythroraycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A l.l,12-cyclic carbamate.
Preparation DD: Formula (1): Rb = F. R2 is -CH2-CC-(4-isoquinolyl)
This is prepared according to the method of Preparation D using 2'-O- benzoyl-6-
O-allyl-l l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-l 5-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3 -oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation EE: Formula (1); Rh F, Ra is -CH2-CC-(3-pyridyl)
This is prepared according to the method of Preparation E using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycm A
11, 12-cyclic carbamate in place of 2'-O- Denzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation FF: Formula (11: Rb, = F. Ra is -CH2-CC-(3-(6-methylquinolyl)
This is prepared according to the method of Preparation F using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladmosyl-11-deoxy-3-oxo-2-fluoro-15-methyletythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation GG: Formula (11: Rb, = F, Ra is -CH2-CC-(3-(6-aminoquinolyl)
This is prepared according to the method of Preparation G using 2'-O- benzoyl-6-
O-allyl-1 l-amino-3-descladinosyl-11-deoxy-3-oxo-2-fluoro-l 5-methylerythromycin A
11, 12-cyclic carbamate in place of 2 -O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation HH: Formula (1). Rb, = F, Rg is -CH2 -CC-(3-(5-isoxazo1-3-
yl)thienyl)
This is prepared according to the method of Preparation H using 2'-O- bcnzoyl-6-
O-allyl-11-amino-3-descladinosyl-11-deoxy-3-oxo-2-fluoro-l5-methylerythromycin A
11, 12-cyclic carbamate in place of 2, -O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-l5-methylerythromycin A 11, 12-cyclic carbamate.
Preparation II: Formula (IV Rb = F, Ra is -CH2-CC-(6-quinolyl)
This is prepared according to the method of Preparation I using 2'-O- benzoyl-6-O-
allyl-1 l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-1 1-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation JJ: Formula (1): Rb = F. Ra is -CH2-CC-(3-quinoxal-6-yl)
This is prepared according to the method of Preparation J using 2,-O- benzoyl-6-O-
allyl-11-amino-3-descladinosyl-11-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-15-methylerythromycin A 11, 12-cyclic carbamate.
Preparation KK: Formula (1): Rb = F, Ra is -CH2-CC-(5-(N-(2-pyridyl)-2-
furamidyl)
This is prepared according to the method of Preparation K using 2'-O- benzoyl-6-
O-allyl-11 -amino-3-descladinosyl-l l-deoxy-3-oxo-2-fluoro-15-methylerythromycin A
11, 12-cyclic carbamate in place of 2'-O- benzoyl-6-O- allyl-l l-amino-3-descladinosyl-11 -
deoxy-3-oxo-15-methylerythrornycin A 11, 12-cyclic carbamate.
Example 27
Compound of Formula (1): L is CO. T is NH, Ra is -CH2-(2,2-dimethyl-1,3-dioxolan-
4-yl), Rc is H
Step 1: Conversion of 3-OH form of compound (1) from Ra is -CH2CH2CH=CH2 to
Ra is -CH2CH(OH)CH2OH, Rc is acetyl.
To a sample of the compound from Example 20, Step 4 (5.0 g, 7.32 mmol, 3-OH
form of compound (1), Ra is -CH2CH=CH2, Rc is acetyl) and N-methylmorpholine N
oxide (1.7 g, 14.5 mmol) in THF (25 mL) at room temperature is added OSO4 (4% in
H2O, 0.090 mL, 0.0147 mmol), and the mixture is stirred for 24 hours. The reaction is
quenched with sodium bisulfite (1.5 g) and water (10 mL), and the solvents are removed
under vacuum. The residue is dissolved in ethyl acetate, which is washed with saturated
aqueous sodium bicarbonate, water and brine, and dried (Na2SO4). The solvent is
removed to give the compound.
Step 2: Conversion of 3-OH form of compound (1) from Ra is
-CH2CH(OH)CH2OH to Ra is -CH2-(2.2-dimethyl-1.3-dioxolan-4-yl). Rc is acetyl.
To a sample of the compound from Step 1 (500 mg, 0.70 mmol) and 2, 2-
dimethoxypropane (0.26 mL, 2.1 mmol) in toluene (7 mL) is added p-toluenesulfonic .
acid (160 mg, 0.84 mmol), and the mixture is stirred at 55°C for 3 days. The mixture is
diluted with ethyl acetate, and this solution is washed with 10% sodium carbonate
solution, water and brine. The organic phase is dried (Na2SO4), and the solvent is
removed to give the crude product, which is purified by chromatography on silica gel,
during with 2:97:1 memanoychloroform/ammonium hydroxide to give the compound.
Step 3: Oxidation of 3-OH to carbonyl to form compound (1): Ra is -CH2-(2, 2-
dimethyl-l, 3-dioxolan-4-yl). Rc is acetyl.
A sample of the compound from Step 2 (356 mg, 0.47 mmol) is oxidized with
N-chlorosuccinimide and dimethylsulfide according to the procedure of Example 16, Step
2, to afford the compound.
Step 4: Deprotection to form compound of Formula (1): L is CO, T is NH, Ra is
-CHz(2,2-dimethyl-1,3-dioxolan-4-yl), Rc is H.
A sample of the compound from Step 3 (100 mg, 0.13 mmol) is stirred in
methanol (4 mL) overnight at room temperature. The solvent is removed, and the residue
is purified by chromatography on silica gel, eluting with 0.9:98:1
methanol/chloroform/ammonium hydroxide to give the compound.
, Optional Step: Conversion of R, is -CH2-(2.2-dimethyl-1.3-dioxolan-4-yl) in
compound (1) to -CH2CH(OH)CH2OH.
A sample of the compound from Step 4 (100 mg, 0.13 mmol) is stirred at reflux
with p-toluenesulfonic acid (35 mg, 0.18 mmol) in 4:1 THF/water (2.5 mL) for 3 hours.
The mixture is diluted with ethyl acetate, and this solution is washed with 10% sodium
carbonate solution, water and brine. The organic phase is dried (Na2SO4), and the solvent
is removed to give the crude product, which is purified by chromatography on silica gel,
eluting with 2:97:1 methanol/chloroform/ammonium hydroxide to give the compound.
Example 28
. Fluorination of C2 Position before 11, 12 Cyclic Ring Formed
Synthesis of 2'-O-berizoyl-6-O- propargyl-3-descladinosyl-3-oxo-10.11 -anhydro-2-fluoro-
15-methylerythromycin A
A solution of 2'-O- benzoyl -6-O-propargyl-3-descladinosyl-3-oxo-10, 11-anhydro-
15-methyl-erythromycin A in tetrahydrofuran under inert atmosphere is cooled to -78°C
and treated with 1.0 M potassium tert-butoxide in tetrahydrofuran. The mixture is stirred
for 5 minutes, and a solution of N-fluorobenzenesulfonimide in tetrahydrofuran is added
in three portions over 2 hours. After addition, the reaction is allowed to warm to ambient
temperature and kept for an additional 5 hours. Aqueous K2CO3 is added, and the
mixture is extracted with CH2C12. The organic extracts are combined, dried over MgSO4,
filtered, and evaporated. Chromatography on silica gel gives the product.
Example 29
Fluorination of C2 Position after Cyclic Carbamate Formed
Synthesis of 2' -O- benzoyl-6-O- allyl-3-descladmosyl-3-oxo-11-deoxy-11-amino-2-fluoro-
15-methylerythromycin A 1.1, 12 cyclic carbamate
To a THF solution (0.5 ml) of 2'-O- benzoyl-6-O- allyl-3-descladinosyl-3-oxo-11-
deoxy-11 -amino- 15-methylerythromycin A 11, 12-cyclic carbamate (100 mg, 0.132 mmol,
1.0 eq) was added a THF solution of potassium tert-butoxide (0.3 ml, 1M, 2.3 eq.) at -
78°C. The reaction mixture was then kept at -60°C to -40°C for 20 min., followed by
introduction of N-Fluorobenzenesulfonimide (46 mg, 0.146 mmol, 1.1 eq.) in THF (0.2
ml) at -78°C. The reaction mixture was kept at -70°C to -40°C for 1 h before it was
allowed to warm to 0°C from -70°C in 1.5 h. It was then diluted with EtOAc, washed
with saturated aqueous NaHCO3, , water, and brine. The organic phase was dried over
MgSO4, filtered, and concentrated. Flash chromatography of the crude product (4:1
hexanes:acetone + 1% Et3N) ylelded 76 mg (74%) of the desired product. 13C- NMR
(100.6 MHz, CDC13) d 217.5, 203 (d, J = 27.6 Hz), 165.5 (d, J= 23.8 Hz), 165.2, 157.5,
135.4, 132.9, 130.4, 129.8, 128.3, 118.0, 101.7, 98 (d, J = 207 Hz), 83.5, 79.1, 78.6, 72.1,
69.4, 64.6, 63.5, 57.5, 44.2.40.7, 40.4, 38.5, 37.3, 31.4, 31.3, 24.9 (d, J =24.3 Hz), 21.0,
20.7, 19.4, 17.7, 15.0, 13.9, 13.7, 13.3.
Example 30
Derivatization of C-13 Position
Starting Material: 15-Aminoerythromycin A diacetate salt
A solution of 15-azidoerythromycin A (7.75 g, 10 mrnol) in 50 mL of methanol is
treated with acetic acid (2.0 mL) and 10% palladium on carbon (0.1 g) and stirred under 1
atm of hydrogen gas until thin-layer chromatographic analysis reveals complete reduction of the starting material. The suspension is filtered through Celite™ to remove the
catalyst, then evaporated to dryness to yleld the product, which is used as a starting
material for the following derivatizations.
Synthesis of 15-(quinol-4-ylacetamido)erythromycin A
A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with quinol-4-ylacetyl chloride (350 mg) and
triethylamine (0.5 mL) at 0°C. After 3 hours, the reaction is diluted with dichloromethane
and washed three times with saturated aqueous NaHCO3. The organic phase is dried over
MgSO4, filtered, and evaporated to yleld the crude product Purification by silica gel
chromatography ylelds the pure product.
B. Synthesis of 15-(3-(quinol-4-yl)propionamido)erythromycin A
A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with 3-(quinol-4-yl)propionyl chloride (400 mg)
and triethylamine (0.5 mL) at 0°C. After 3 hours, the reaction is diluted with
dichloromethane and washed three times with saturated aqueous NaHCO3. The organic
phase is dried over MgSO4, filtered, and evaporated to yleld the crude product
Purification by silica gel chromatography ylelds the pure product.
Synthesis of 15-(, isoquinol-4-ylacetamido)erythromycin A
A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with isoquinol-4-ylacetyl chloride (350 mg) and
triethylamine (0.5 mL) at 0°C. After 3 hours, the reaction is diluted with dichloromethane
and washed three times with saturated aqueous NaHCO3. The organic phase is dried over
MgSO4, filtered, and evaporated to yleld the crude product. Purification by silica gel
chromatography ylelds the pure product
D. Synthesis of 15-(3-(isoquinol-4-yl)propionamido)erythromycin A
A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with 3-(isoquinol-4-yl)propionyl chloride (400
mg) and triethylamine (0.5 mL) at 0°C. After 3 hours, the reaction is diluted with
dichloromethane and washed three times with saturated aqueous NaHCO3. The organic
phase is dried over MgSO4, filtered, and evaporated to yleld the crude product.
Purification by silica gel chromatography yletds the pure product.
Synthesis of 15-((quinol-5-ylamino)acetamido)erythromycin A
A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with (quinol-5-ylamino)acetic acid (0.30 g),
dicyclohexylcarbodiimide (0.4 g), 1-hydroxybenzotriazole (0.25 g), and triethylamine
(0.5 mL) at 0°C. After 3 hours, the reaction is diluted with dichloromethane and washed
three times with saturated aqueous NaHCO3. The organic phase is dried over MgSO4,
filtered, and evaporated to yleld the crude product. Purification by silica gel
chromatography ylelds the pure product.
F. Synthesis of 15-((quinol-6-ylamino)acetamido)erythromycin A
A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with (quinol-6-ylamino)acetic acid (0.30 g),
dicyclohexylcarbodiimide (0.4 g), 1-hydroxybenzotriazole (0.25 g), and triethylamine
(0.5 mL) at 0°C. After 3 hours, the reaction is diluted with dichloromethane and washed
three times with saturated aqueous NaHCO3. The organic phase is dried over MgSO4,
filtered, and evaporated to yleld the crude product. Purification by silica gel
chromatography ylelds the pure product.
G. Synthesis of 15-((quinol-4-ylmethyl)carbamoylamino)erythromycin A

A solution of 15-aminoerythromycin A diacetate salt (1.0 g) in 10 mL of
dichloromethane is treated sequentially with quinoline-4-methoxycarbonyl chloride (400
mg) and triethylamine (0.5 mL) at 0°C. After 3 hours, the reaction is diluted with
dichloromethane and washed three times with saturated aqueous NaHCO3. The organic
phase is dried over MgSO4, filtered, and evaporated to yleld the crude product.
Purification by silica gel chromatography ylelds the pure product.
Example 31
6-O- methyl-3-descladinosyl-3-oxo-11-deoxy-l l-amino-15-(3-(quinol-4-
yl)propionamido)erythromycin A 11, 12-cyclic carbamate

This is prepared according to the procedures described in Example 30, starting
with 15-(3-(quinol-4-yl)propionamido)erythromycin A.
Example 32
6-O- methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-2-fluoro-l 5-(3-(quinol-4-
yl)propionamido)erythromycin A 11, 12-cyclic carbamate
Step 1. To a solution of 2'-O- benzoyl-6-O- methyl-3-descladinosyl-3-oxo-11-
deoxy-1 l-amino-15-(3-(quinol-4-yl)propionamido)erythromycin A 11, 12-cyclic
carbamate in THF is added a THF solution of potassium tert-butoxide (2.3 eq.) at -78°C.
The reaction mixture is then kept at -60°C to -40°C for 20 min., followed by
introduction of N-Fluorobenzenesulfonimide (1.1 eq.) in THF (0.2 ml) at -78°C. The
reaction mixture is kept at -70°C to -40°C for 1 h before it is allowed to warm to 0°C
from -70° C in 1.5 h. It is then diluted with EtOAc, washed with saturated aqueous
NaHCO3, water, and brine. The organic phase is dried over MgSO4, filtered, and
concentrated. Flash chromatography yields the desired product as the 2'-O- benzoate.
Step 2. The product of Step 1 is dissolved in 1 mL of methanol, sealed, and
refluxed at 80 °C for 16h. Volatiles are removed under reduced pressure. Flash
chromatography ylelds the desired product.
Example 33
2'-O-Benzoyl-6-O- methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-1 5-
ethenylerythromycin A 11.12-cyclic carbamate
This is prepared according to the procedures described previously, starting with
15-ethenylerythromycin A.
Example 34
6-O-methyl-3-descladinosyl-3-oxo-l l-deoxy-11-amino-15-ethenylerythrornycin A 11.12
cyclic carbamate
2'-O- Benzoyl-6-O- methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-l 5-
ethenylerythromycin A 11, 12-cyclic carbamate from Example 33 is dissolved in 1 mL of
methanol, sealed, and refluxed at 80 °C for 16 h. Volatiles are removed under reduced
pressure. Flash chromatography ylelds the desired product
Example 35
6-O-methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-2-f1uoro-15-ethenylerythromycin
A 11,12-cyclic carbamate
Step 1. To a solution of 2'-O- benzoyl-6-O- methyl-3-descladinosyl-3-oxo-11-
deoxy-11-amino-15-ethenylerythromycin A11 , 12-cyclic carbamate in THF is added a
THF solution of potassium tert-butoxide (2.3 eq.) at -78°C. The reaction mixture is then
kept at -60°C to -40°C for 20 min., followed by introduction of N-
Fluorobenzenesulfonimide (1.1 eq.) in THF (0.2 ml) at -78°C. The reaction mixture is
kept at -70°C to -40°C for 1 h before it is allowed to warm to 0°C from -70°C in 1.5 h.
It is then diluted with EtOAc, washed with saturated aqueous NaHCO3, water, and brine.
The organic phase is dried over MgSO4, filtered, and concentrated. Flash
chromatography ylelds the desired product as the 2-O-benzoate.
Step 2. The product of Step 1 is dissolved in 1 mL of methanol, sealed, and
refluxed at 80 °C for 16 h. Volatiles are removed under reduced pressure. Hash
chromatography ylelds the desired product.
Example 36
6-O- Methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-2-fluoro-15-( 2-( 3-
quinolyl)ethenyl)erythromycin A 11,12-cyclic carbamate
Step 1: 2'-O- Benzoyl-6-O- methyl-11 -amino-3-descladinosyl-l l-deoxy-3-oxo-l 5-
ethenylerythromycin A 1 l;12-cyclic carbamate (40 mg), tris(dibenzylideneacetone)
dipalladium(O)-chloroform adduct (14 mg), tri-o-tolylphosphine (17 mg), and 3-
bromoquinoline (72 µl) are placed in a round-bottom flask which is flushed with N2.
Degassed acetonitrile (1 mL) and freshly distilled Et3N (0.015 ml) are added. The
reaction is refluxed for 63 h. The mixture is returned to ambient temperature and diluted
with 40 mL of EtOAc. The solution is washed successively with 10 mL each of saturated
aqueous NaHCO3, water, and brine. The organic phase is dried over MgSO4, filtered, and
concentrated. Flash chromatography of the crude product ylelds the desired product.
Step 2: The product of Step 1 is dissolved in 1 mL of methanol, sealed, and
refluxed at 80 °C for 16 h. Volatiles are removed under reduced pressure. Flash
chromatography ylelds the desired product.
Example 37
6-O- Methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-2-fluoro-15-( 2-( 3-
quinolyl)ethenyl)erythromycin A 11,12-cyclic carbamate
Step 1:2'-O- Benzoyl-6-O- methyl-l l-amino-3-descladinosyl-l l-deoxy-3-oxo-2-
fluoro-15-ethenylerythromycin A 11, 12-cyclic carbamate (40 mg),
tris(dibenzylideneacetone) dipalladium(O)-chloroform adduct (14 mg), tri-o-
tolylphosphine (17 mg), and 3-bromoquinoline (72 µl) are placed in a round-bottom flask
which is flushed with N2. Degassed acetonitrile (1 mL) and freshly distilled Et3N (0.015
ml) are added. The reaction is refluxed for 63 h. The mixture is returned to ambient
temperature and diluted with 40 mL of EtOAc. The solution is washed successively with
10 mL each of saturated aqueous NaHCO3, water, and brine. The organic phase is dried
over MgSO4, filtered, and concentrated. Flash chromatography of the crude product
ylelds the desired product.
Step 2: The product of Step 1 is dissolved in 1 mL of methanol, sealed, and
refluxed at 80 °C for 16 h. Volatiles are removed under reduced pressure. Flash
chromatography ylelds the desired product.
Example 38
6-O- methyl-3-descladinosyl-3-oxo-11-deoxy-11-amino-2-fluoro-15-( 2-( 3-
quinolylmethyl)ethenyl)erythromycin A 11,12-cyclic carbamate
Step 1: A mixture of 2'-O- benzoyl-6-O- methyl-11-amino-3-descladinosyl-11-
deoxy-3-oxo-2-fluoro-15-ethenylerythromycin A11, 12-cyclic carbamate, 3-
allylquinoline, and bis(triphenylphosphine)benzylidenerhodium chloride is heated in
refluxing benzene for 8 hours. The mixture is returned to ambient temperature and
diluted with 40 mL of EtOAc. The solution is washed successively with 10 mL each of
saturated aqueous NaHCO3, water, and brine. The organic phase is dried over MgSO4,
filtered, and concentrated. Flash chromatography of the crude product ylelds the desired
product.
Step 2: The product of Step 1 is dissolved in 1 mL of methanol, sealed, and
refluxed at 80 °C for 16 h. Volatiles are removed under reduced pressure. Flash
chromatography ylelds the desired product.
Claims
1. A compound of the formula
or a pharmaceutically acceptable salt thereof wherein
Ra is substituted or unsubstituted aryl (4-14C); substituted or unsubstituted
arylalkyl (5-20C); substituted or unsubstituted arylalkenyl (5-20C); substituted or unsubstituted
arylalkynyl (5-20C);
Rb is H or halogen;
Rd is fluoroethyl; and
Rf is H or C1-C3 alkyl.
2. The compound as claimed in claim 1 wherein Rb is H.
3. The compound as claimed in claim 1 wherein Rb is halogen.
4. The compound as claimed in claim 1 wherein Rb is fluoro.
5. The compound as claimed in claim 1 wherein Rf is H.
6. The compound as claimed in claim 1 wherein Rf is C1-C3 alkyl.
7. The compound as claimed in claim 1 wherein Rf is methyl.
8. The compound as claimed in claim 1 wherein Ra is substituted or unsubstituted
aryl(4-14C).
9. The compound as claimed in claim I wherein Ra is substituted or unsubstituted
arylalkyl (5-20C).
10. The compound as claimed in claim 1 wherein Ra is substituted or unsubstituted
arylalkenyl (5-20C).
11. The compound as claimed in claim 1 wherein Ra is substituted or unsubstituted
arylalkynyl (5-20C).
12. The compound as claimed in claim 1 wherein Ra is 3-aryl-prop-2-enyl
or 3-aryl-prop-2-ynyl.
13. The compound as claimed in claim 12 wherein said aryl is 3-quinolyl, 4-quinolyl,
5-quinolyl, phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methoxyphenyl, 6-quinolyl, 6-quinoxalyl,
6-amino-3-quinolyl, or 4-isoquinolyl.
14. The compound as claimed in claim 1 wherein Ra is 3-aryl-prop-2-ynyl.
15. The compound as claimed in claim 14 wherein said aryl is 3-quinolyl, 4-quinolyl,
5-quinolyl, phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methoxyphenyl, 6-quinolyl, 6-quinoxalyl,
6-amino-3-quinolyl, or 4-isoquinolyl.
16. A pharmaceutical composition comprising an effective amount of the compound
as claimed in claim 1 in admixture with a pharmaccutically acceptable excipient.
17. A compound as claimed in claim 1, or a pharmaceutical composition thereof for
controlling infection.
18. A compound as claimed in claim 1, for preserving a material from microbial
decay.
19. A compound of the formula
Ra is substituted or unsubstituted arylalkyl (5-20C); substituted or unsubstituted
arylalkenyl (5-20C); or substituted or unsubstituted arylalkynyl (5-20C);
Rb is H or F; and, Rd is fluoroethyl.
20. The compound as claimed in claim 19 wherein
Ra is substituted or unsubstituted arylalkynyl.
21. The compound as claimed in claim 19 wherein
Ra is substituted or unsubstituted arylalkenyl.
22. The compound as claimed in claim 19 wherein
Ra is 3-aryl-prop-2-ynyl.
23. The compound as claimed in claim 19 wherein
Ra is 3-aryl-prop-2-enyl.
24. The compound as claimed in claim 23 wherein the aryl is 3-quinolyl, 4-quinolyl,
5-quinolyl, phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methoxyphenyl, 6-quinolyl, 6-quinoxalyl,
6-amino-3-quinolyl, or 4-isoquinolyl.
25. The compound as claimed in claim 23 wherein
Ra is 3-(6-quinoxalyl)-prop-2-enyl; and
Rb is H.
26. The compound as claimed in claim 23 wherein
Ra is 3-(3-quinolyl)-prop-2-enyl; and
Rb is H.
27. The compound as claimed in claim 23 wherein
Ra is 3-(6-quinoxalyl)-prop-2-enyl; and
Rb is F.
28. The compound as claimed in claim 23 wherein
Ra is 3-(3-quinolyl)-prop-2-enyl; and
Rb is F.
29. A compound of the formula
wherein
Ra is C1-C3 alkyl;
Rd is fluoroethyl; and
Rf is substituted or unsubstituted aryl (4-14C); substituted or unsubstituted
arylalkyl (5-20C).
30. The compound as claimed in claim 29 wherein Ra is methyl.
31. The compound as claimed in claim 30 wherein Rf is substituted or unsubstituted
arylalkyl (5-20C).
32. A compound of the formula
wherein
Ra is C1-C3 alkyl;
Rb is halogen;
Rd is fluoroethyl; and
Rf is substituted or unsubstituted aryl (4-14C); or substituted or unsubstituted
arylalkyl (5-20C).
33. The compound as claimed in claim 32 wherein Rb is fluoro.
34. The compound as claimed in claim 33 wherein Ra is methyl.
35. The compound as claimed in claim 34 wherein Rf is substituted or unsubstituted
arylalkyl (5-20C).

Compounds of formula (1), (2) or
(3), wherein Ra is H; substituted or unsub-
stituted alkyl (1-10C); substituted or un-
substituted alkenyl (2-10C); substituted or
unsubstituted alkynyl (2-10C); substituted
or unsubstituted aryl (4-14C); substituted
or unsubstituted arylalkyl (5-20C); or ORa
is replaced by H; Rb is H or halogen; Rc
is H or a protecting group; Rd is methyl, unsubstituted alkyl (3-10C); substituted
alkyl (1-10C); substituted or unsubstituted
alkynyl (2-10C); substituted or unsubsti-
tuted aryl (4-14C); substituted or unsub-
stituted arylalkyl (5-20C); substituted or
unsubstituted arylalkenyl (5-20C); substi-
tuted or unsubstituted arylalkynyl (5-20C);
substituted or unsubstituted amidoarylalkyl
(5-20C); substituted or unsubstituted ami-
doarylalkenyl (5-20C); or substituted or
unsubstituted amidoarylalkynyl (5-20C);
Rc is H or a protecting group; L is
methylene or carbonyl; T is -O-, -N(R)-, -N(OR)-, -N(NHCOR)-, -N(N-CHR)-,
or -N(NHR)- wherein R is H or Ra as de-
fined above, with the proviso that when L
is methylene, T is -O-; one of Z and Y is
H and the other is OH, protected OH, or
amino, mono- or dialkylamino, protected
amino, or an amino heterocycle or Z and
Y together are -O, -NOH or a derivatized
oxime; including any pharmaceutically acceptable salts thereof and any stereoisomeric forms and mixtures of stereoisomeric forms thereof, are antimicrobial agents.

Documents:

in-pct-2001-1066-kol-abstract.pdf

in-pct-2001-1066-kol-assignment.pdf

in-pct-2001-1066-kol-claims.pdf

in-pct-2001-1066-kol-correspondence.pdf

in-pct-2001-1066-kol-description (complete).pdf

in-pct-2001-1066-kol-drawings.pdf

in-pct-2001-1066-kol-examination report.pdf

in-pct-2001-1066-kol-form 1.pdf

in-pct-2001-1066-kol-form 13.pdf

in-pct-2001-1066-kol-form 18.pdf

in-pct-2001-1066-kol-form 3.pdf

in-pct-2001-1066-kol-form 5.pdf

in-pct-2001-1066-kol-gpa.pdf

in-pct-2001-1066-kol-reply to examination report.pdf

in-pct-2001-1066-kol-specification.pdf

in-pct-2001-1066-kol-translated copy of priority document.pdf


Patent Number 235061
Indian Patent Application Number IN/PCT/2001/1066/KOL
PG Journal Number 26/2009
Publication Date 26-Jun-2009
Grant Date 24-Jun-2009
Date of Filing 11-Oct-2001
Name of Patentee KOSAN BIOSCIENCES INC.
Applicant Address 3832 BAY CENTER PLACE, HAYWARD, CALIFORNIA 94545, USA.
Inventors:
# Inventor's Name Inventor's Address
1 CHU, DANIEL T.W. 3767 BENTON STREET, SANTA CLARA, CALIFORNIA 95051
2 ASHLEY GARY W 102 VERDEMAR DRIVE, ALAMEDA CALIFORNIA 94502
PCT International Classification Number C07H 17/08
PCT International Application Number PCT/US2000/09914
PCT International Filing date 2000-04-14
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/172,159 1999-12-17 U.S.A.
2 60/140,175 1999-06-18 U.S.A.