Seco-mevinic acid derivatives useful as antihypercholesterolemic agents and new intermediates

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FIELD OF THE INVENTION

The present invention relates to secomevinic acid derivatives which are HMG CoA reductase inhibitors and thus are useful as antihypercholesterolemic agents and to new intermediates employed in preparing such compounds.

BACKGROUND OF THE INVENTION

F. M. Singer et al., "New Inhibitors of in vitro Conversion of Acetate and Mevalonate to Cholesterol", Proc. Soc. Exper. Biol. Med., 102, 370 (1959) and F. H. Hulcher, "Inhibition of Hepatic Cholesterol Biosynthesis by 3,5-Dihydroxy-3,4,4,-trimethylvaleric Acid and its Site of Action," Arch. Biochem. Biophys., 146, 422 (1971) disclose that certain mevalonate derivatives inhibit the biosynthesis of cholesterol.

Singer et al. reported that fluoromevalonic acid is more effective in inhibiting biosynthesis of cholesterol (as measured by in vitro conversion of labeled acetate and labeled mevalonate into cholesterol) than .DELTA.4-androstene-17.alpha.-ol-3-one-17.beta.-oic acid and .DELTA.1-testololactone.

Hulcher reported that an analog of mevalonic acid, namely, 3,5-dihydroxy-3,4,4-trimethylvaleric acid strongly inhibits cholesterol biosynthesis by rat liver homogenates.

U.S. Pat. No. 3,983,140 to Endo et al. discloses the fermentation product ML-236B referred to generically as compactin ##STR3## (also referred to as mevastatin) which is prepared by cultivation of a microorganism of the genus Penicillium. This fermentation process is disclosed in U.S. Pat. No. 4,049,495 issued Sep. 20, 1977 to Endo et al.

Brown, A. G., et al., (Beecham Pharmaceuticals Research Div.), "Crystal and Molecular Structure of Compactin, a New Antifungal Metabolite from Penicillium Brevicompactum", J. Chem. Soc. Perkin I. 1165-1170 (1976) confirms that compactin has a complex mevalonolactone structure as disclosed by Endo et al. in the above patents.

U.S. Pat. No. 4,231,938 to Monaghan et al. discloses mevinolin (lovastatin, Monacolin K) ##STR4## (also referred to as MK-803) which is prepared by culturing a microorganism of the genus Aspergillus.

U.S. Pat. No. 4,346,227 to Terahara et al discloses pravastatin ##STR5##

Pravastatin is prepared by the enzymatic hydroxylation of compactin or its carboxylic acid as disclosed in U.S. Pat. No. 4,410,629 to Terahara et al.

U.S. Pat. No. 4,448,979 issued May 15, 1984 to Terahara et al discloses the lactone of pravastatin.

U.S. Pat. Nos. 4,444,784 and 4,450,171 to Hoffman et al disclose various antihypercholesterolemic compounds including synvinolin (simvastatin) ##STR6## as well as compounds of the structures ##STR7## wherein R.sup.1 is H or CH.sub.3, R can be an alkyl group including ##STR8## X, Y and Z are single and/or double bonds in all possible combinations.

European Patent Application 0065835A1 filed by Sankyo discloses cholesterol biosynthesis inhibiting compounds of the structure ##STR9## and their corresponding free carboxylic acids, which may be represented by the following formula ##STR10## (in which one of R.sup.1 and R.sup.2 represents a hydrogen atom and the other represents a hydroxy group), and salts and esters of the carboxylic acids.

European Patent Application 0142146A2 filed by Merck discloses mevinolin-like compounds of the structure ##STR11## wherein R.sup.1 is

1) hydrogen,

2) C.sub.1-4 alkyl

3) 2,3-dihydroxypropyl,

4) alkali metal cation, such as Na.sup.+, or K.sup.+, or

5) ammonium of formula NR.sup.3 R.sup.4 R.sup.5 R.sup.6 wherein R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are independently hydrogen or C.sub.1-4 alkyl or two of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are joined together to form a 5 or 6-membered heterocycle such as pyrrolidino or piperidino with the nitrogen to which thy are attached;

E is --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--, or --(CH.sub.2).sub.3 --; and Z is ##STR12## wherein the dotted lines represent all of the possible oxidation states of the bicyclic system such as naphthalene, dihydro-, tetrahydro-, hexahydro-, octahydro-, and decahydronaphthalene;

X is --O-- or NR.sup.9 wherein

R.sup.9 is H or C.sub.1-3 alkyl;

R.sup.7 is C.sub.2-8 alkyl; and

R.sup.8 is H or --CH.sub.3 ; ##STR13## wherein R.sup.10, R.sup.11 and R.sup.12 are independently a) hydrogen,

b) halogen, such as bromo, chloro or fluoro,

c) C.sub.1-4 alkyl,

d) halo-C.sub.1-4 alkyl,

e) phenyl either unsubstituted or substituted with one or more of

i) C.sub.1-4 alkyl,

ii) C.sub.1-4 alkyl,

iii) C.sub.2-8 alkanoyloxy, or

iv) halo-C.sub.1-4 alkyl,

v) halo, such as bromo, chloro or fluoro,

f) OR.sup.13 wherein R.sup.13 is

i) hydrogen,

ii) C.sub.1-8 alkanoyl,

iii) benzoyl,

iv) phenyl,

v) halophenyl,

vi) phenyl-C.sub.1-3 alkyl, either unsubstituted or substituted with one or more halogen, C.sub.1-4 alkoxy, C.sub.1-4 alkyl or halo-C.sub.1-4 alkyl,

vii) C.sub.1-9 alkyl,

viii) cinnamyl,

ix) halo-C.sub.1-4 alkyl,

x) allyl,

xi) C.sub.3-6 cycloalkyl-C.sub.1-3 alkyl,

Xii) adamantyl-C.sub.1-3 alkyl, ##STR14## wherein n is 0-2, and R.sup.14 is halo such as chloro, bromo or fluoro, or C.sub.1-4 alkyl, and ##STR15## wherein the dotted lines represent possible double bonds there being 0, 1 or 2 double bonds; m represents 1, 2 or 3; and

R.sup.15 is

1) methyl,

2) hydroxy,

3) C.sub.1-4 alkoxy,

4) oxo or

5) halo.

In the discussion of the prior art at pages 2 and 3 of the above European patent, it is indicated that HMG CoA reductase inhibitors reported in the patent literature and elsewhere include compactin; mevinolin, di- and tetrahydro derivatives thereof; analogs with different esters in the 8-position of the polyhydronaphthalene moiety, totally synthetic analogs, wherein the polyhydronaphthalene moiety is replaced by substituted mono- and bicyclic aromatics. The applicant states at pages 3 and 4 as follows:

"But in all instances the active compound included a 4-hydroxytetrahydropyran-2-one ring or the corresponding 3,5-dihydroxy acid, or derivatives thereof, formed by opening the pyranone ring such as: ##STR16## In all of these compounds the 3,5-dihydroxy acid or corresponding lactone moiety is present and the particular stereochemistry depicted is essential for manifestation of the optimum enzyme inhibitory activity."

GB 1,586,152 discloses a group of synthetic compounds of the formula ##STR17## in which E represents a direct bond, a C.sub.1-3 alkylene bridge or a vinylene bridge and the various R's represent a variety of substituents.

The activity reported in the U.K. patent is less than 1% that of compactin.

U.S. Pat. No. 4,375,475 to Willard et al discloses hypocholesterolemic and hypolipemic compounds having the structure ##STR18## wherein A is H or methyl; E is a direct bond, --CH.sub.2 --, --CH.sub.2 --CH.sub.2 l--, --CH.sub.2 --CH.sub.2 --CH.sub.2 -- or --CH.dbd.CH--; R.sub.1, R.sub.2 and R.sub.3 are each selected from H, halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, phenyl, phenyl substituted by halogen, C.sub.1-4 alkoxy, C.sub.2-8 alkanoyloxy, C.sub.1-4 alkyl, or C.sub.1-4 haloalkyl, and OR.sub.4 in which R.sub.4 is H, C.sub.2-8 alkanoyl, benzoyl, phenyl, halophenyl, phenyl C.sub.1-3 alkyl, C.sub.1-9 alkyl, cinnamyl, C.sub.1-4 haloalkyl, allyl, cycloalkyl-C.sub.1-3 -alkyl, adamantyl-C.sub.1-3 -alkyl, or substituted phenyl C.sub.1-3 -alkyl in each of which the substituents are selected from halogen, C.sub.1-4 alkoxy, C.sub.1-4 alkyl, or C.sub.1-4 haloalkyl; and the corresponding dihydroxy acids resulting from the hydrolytic opening of the lactone ring, and the pharmaceutically acceptable salts of said acids, and the C.sub.1-3 alkyl and phenyl, dimethylamino or acetylamino substituted C.sub.1-3 -alkyl esters of the dihydroxy acids; all of the compounds being the enantiomers having a 4 R configuration in the tetrahydropyran moiety of the trans racemate shown in the above formula.

GB 2162-179-A discloses napthyl analogues of mevalolactone useful as cholesterol biosynthesis inhibitors having the structure ##STR19## wherein R.sub.1 =1-3C alkyl; Z is a gp. of formula Z.sub.1 or Z.sub.2 : ##STR20## R.sub.7 =H, a hydrolysable ester gp. or a cation.

European Patent No. 164-698-A discloses preparation of lactones useful as anti-hypercholesterolemic agents by treating an amide with an organic sulphonyl halide R.sup.5 SO.sub.2 X, then removing the protecting group Pr. ##STR21## wherein X=halo;

Pr=a carbinol-protecting group;

R.sup.1 =H or CH.sub.3 ;

R.sup.3, R.sup.4 =H, 1-3C alkyl or phenyl-(1-3C alkyl), the phenyl being optionally substituted by 1-3C alkyl, 1-3C alkoxy or halo;

R.sup.2 =a group of formula (A) or (B): ##STR22## R.sup.6 =H or OH; R=H or CH.sub.3 ;

a, b, c and d=optional double bonds;

R.sup.7 =phenyl or benzyloxy, the ring in each case being optionally substituted by 1-3C alkyl or halo;

R.sup.8, R.sup.9 =1-3C alkyl or halo;

R.sup.5 =1-3C alkyl, phenyl or mono- or di-(1-3C alkyl)phenyl.

Anderson, Paul Leroy, Ger. Offen. DE 3,525,256 discloses naphthyl analogs of mevalonolactones of the structure ##STR23## wherein R.sup.1 is alkyl, Z=Q, Q.sup.1 ; R.sup.7 =H, or a hydrolyzable ester group useful as inhibitors of cholesterol biosynthesis and in treatment of atherosclerosis.

WO 8402-903 (based on U.S. application Ser. No. 460,600, filed Jan. 24, 1983) filed in the name of Sandoz AG discloses mevalono-lactone analogues useful as hypolipoproteinaemic agents having the structure ##STR24## wherein the two groups Ro together form a radical of formula ##STR25## wherein R.sub.2 is hydrogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, (except t-butoxy), trifluoromethyl, fluoro, chloro, phenoxy or benzyloxy,

R.sub.3 is hydrogen, C.sub.1-3 alkyl, C.sub.1-3 alkoxy, trifluoromethyl, fluoro, chloro, phenoxy or benzyloxy, with the provisos that not more than one of R.sub.2 and R.sub.3 is trifluoromethyl, not more than one of R.sub.2 and R.sub.3 is phenoxy, and not more than one of R.sub.2 and R.sub.3 is benzyloxy,

R.sub.1 is hydrogen, C.sub.1-6 alkyl, fluoro, chloro or benzyloxy,

R.sub.4 is hydrogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, (except t-butoxy), trifluoromethyl, fluoro, chloro, phenoxy or benzyloxy,

R.sub.5 is hydrogen, C.sub.1-3 alkyl, C.sub.1-3 alkoxy, trifluoromethyl, fluoro, chloro, phenoxy or benzyloxy,

R.sub.5a is hydrogen, C.sub.1-2 alkyl, C.sub.1-2 alkoxy, fluoro or chloro, and with the provisos that not more than one of R.sub.4 and R.sub.5 is trifluoromethyl, not more than one of R.sub.4 and R.sub.5 is phenoxy and not more than one of R.sub.4 and R.sub.5 is benzyloxy, ##STR26## wherein n is 0, 1, 2 or 3 and both q's are 0 or one is 0 and the other is 1,

Z is ##STR27## wherein R.sub.6 is hydrogen or C.sub.1-3 alkyl, with the general proviso that -X-Z and the R.sub.4 bearing phenyl group are ortho to each other;

in free acid form or in the form of a physiologically-hydrolysable and acceptable ester or a 6 lactone thereof or in salt form.

WO 8603-488-A (Sandoz AG) discloses indene analogues of mevalolactone, useful as hypolipoproteinaemia and anti-atherosclerotic agents, in free acid form or in the form of an ester or delta-lactone or in salt form which have the formula ##STR28## R=H or primary or secondary 1-6C alkyl; R.sub.1 =primary or secondary 1-6C alkyl; or R+R.sub.1 =(CH.sub.2).sub.m or (Z)--CH.sub.2 --CH.dbd.CH--CH.sub.2 ;

m=2-6;

R.sub.o =1-6C alkyl, 3-7C cycloalkyl or R.sub.4, R.sub.5, R.sub.6 -substituted phenyl;

R.sub.2, R.sub.4 =H, 1-4C alkyl, 1-4C alkoxy (except t-butoxy), CF.sub.3, F, Cl, phenoxy or benzyloxy;

R.sub.3 and R.sub.5 =H, 1-3C alkyl, 1-3C alkoxy, CF.sub.3, F, Cl, phenoxy or benzyloxy;

R.sub.6 =H, 1-2C alkyl, 1-2C alkoxy, F or Cl;

provided that there may only be one each of CF.sub.3, phenoxy or benzyloxy on each of the phenyl and indene rings;

X=(CH.sub.2)n or --(CH.sub.2).sub.q --CH.dbd.CH(CH.sub.2).sub.q --;

n=1-3;

both q's=0, or one is 0 and the other is 1;

Z=--Q--CH.sub.2 --C(R.sub.10)(OH)--CH.sub.2 COOH, in free acid form or in the form of an ester or delta-lactone or salt;

Q=CO, --C(OR.sub.7).sub.2 -- or CHOH;

R'.sub.7s =the same primary or secondary 1-6C alkyl, or together are (CH.sub.2).sub.2 or (CH.sub.2).sub.3 ;

R.sub.10 =H or 1-3C alkyl;

provided that Q may be other than CHOH only when X is CH.dbd.CH or CH.sub.2 --CH.dbd.CH and/or R.sub.10 is 1-3C alkyl.

Heathcock, J. Med. Chem., 1989, 32, 197 discloses the synthesis of a monocyclic compound of the structure ##STR29## However, this compound is relatively inactive as an HG CoA reductase inhibitor.

DESCRIPTION OF THE INVENTION

In accordance with the present invention, compounds are provided having the structure ##STR30## and include all stereoisomers thereof, wherein Z is ##STR31## R is H, lower alkyl or metal ion such as an alkali metal, e.g. Na, Li or K.

R.sup.1 is H, lower alkyl, aryl, lower alkoxy, cycloalkyl, heteroalkyl, aralkyl, heteroaralkyl or heterocyclic;

R.sup.2 is lower alkyl, cycloalkyl or aralkyl, preferably ##STR32## wherein R.sup.3 is H or lower alkyl; n is 1, 2 or 3; and X is O or NR.sup.5 wherein R.sup.5 is H or lower alkyl, and R.sup.4 is lower alkyl, lower thioalkyl, or ##STR33## wherein m is 0, 1, 2 or 3, p is 0, 1 or 2 and R.sup.6 is halogen, lower alkyl, hydroxy or lower alkoxy.

Thus, the compounds of the invention include the following types of compounds. ##STR34##

Preferred are compounds of structure I wherein R.sup.1 is H, R.sup.2 is ##STR35## R.sup.3 is CH.sub.3, X is O or NH and Z ##STR36##

The term "lower alkyl" or "alkyl" as employed herein includes both straight and branched chain radicals of up to 12 carbons, preferably 1 to 8 carbons, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl, the various branched chain isomers thereof, and the like as well as such groups including a halo-substituent, such as F, Br, Cl or I or CF.sub.3, alkoxy, aryl, alkylaryl, haloaryl, cycloalkyl, alkylcycloalkyl, hydroxy, alkoxycarbonyl, alkanoyloxy, aroyloxy, alkylthio, alkylsulfinyl, alkylsulfonyl, arylthio, arylsulfinyl and/or arylsulfonyl.

The term "cycloalkyl" includes saturated cyclic hydrocarbon groups containing 3 to 12 carbons, preferably 3 to 8 carbons, which include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl, any of which groups may be substituted with 1 or 2 of the following groups: halogen, lower alkoxy, lower alkyl, hydroxy, lower alkoxycarbonyl, lower alkanoyl, aroyl, aryl, alkylthio, alkylsulfinyl, alkylsulfonyl, cycloalkylthio, cycloalkylsulfinyl, cycloalkylsulfonyl, arylthio and/or oxo.

The term "aryl" or "Ar" as employed herein refers to monocyclic or bicyclic aromatic groups containing from 6 to 10 carbons in the ring portion, such as phenyl, naphthyl, substituted phenyl or substituted naphthyl wherein the substituent on either the phenyl or naphthyl may be 1 or 2 of the following groups, lower alkyl, halogen (Cl, Br, F or CF.sub.3), lower alkoxy, nitro, alkoxy and/or cyano.

The term "aralkyl", "aryl-alkyl" or "aryl-lower alkyl" as used herein refers to lower alkyl groups as discussed above having an aryl substituent, such as benzyl.

The term "lower alkoxy", "alkoxy" or "aralkoxy" includes any of the above lower alkyl, alkyl or aralkyl groups linked to an oxygen atom.

The term "halogen" or "halo" as used herein refers to chlorine, bromine, fluorine or iodine, with chlorine being preferred.

The term "lower alkenyl" as used herein refers to straight or branched chain radicals of 2 to 12 carbons, preferably 2 to 6 carbons in the normal chain, which include one double bond in the normal chain, such as 2-propenyl, 3-butenyl, 2-butenyl, 4-pentenyl, 3-pentenyl, 2-hexenyl, 3-hexenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 3-octenyl, 3-nonenyl, 4-decenyl, 3-undecenyl, 4-dodecenyl and the like.

The terms "alkanoyl" and "aroyl" refer to a lower alkyl group linked to a carbonyl group or an aryl group linked to a carbonyl group.

The term "haloalkyl" as used herein refers to any of the lower alkyl groups defined above substituted with a halogen as defined above, for example CH.sub.2 F, CF.sub.3 and the like.

The term "metal ion" refers to alkali metal ions such as sodium, potassium or lithium and alkaline earth metal ions such as magnesium and calcium.

The term "heteroaryl" as used herein refers to a 5 to 10 membered mono or bicyclic ring which includes one or two hetero atoms, namely, N, S or O, such as 3-pyrrolyl, 2-imidazolyl, 2-thiazolyl, 2-oxazolyl, 3-pyridyl, 2-pyridyl, 3-aminopyridinyl, pyrazinyl, 2-pyrimidinyl, 2-indolizinyl, 2-thienyl, 3-furyl, 2-quinolyl, 1-indolyl, 5-isothiazolyl, 5-isoxazoyl, and the like.

The term heteroaralkyl as used herein refers to any of the above hetero groups linked to an alkylene group.

The term "heterocyclic" or "hetero" as used herein alone or a part of another group refers to 5- to 10-membered, preferably 5 to 8 membered, monocyclic or bicyclic heterocyclic rings containing 1 or 2 hetero atoms such as N; N and O; and N and S and includes piperidino, pyrrolidino, morpholino, thiamorpholino, piperazino, homopiperazino, piperidinyl, pyrrolidinyl, piperazinyl, morpholinyl, thiamorpholinyl, histaminyl, and the like.

The compounds of the invention may be prepared as described below.

The method for preparing the compounds of formula I wherein X is 0, that is compounds of formula IA, is set out in the following Reaction Scheme I.

The method for preparing compounds of formula I where X is NR.sup.5, that is compounds of formula IB, is set out in the following Reaction Scheme II. ##STR37##

Referring to the Reaction Scheme I set out hereinbefore, compounds of formula IA (X is O) are prepared starting with pravastatin (compound II) which is converted to the corresponding free acid by treating II with mild aqueous acid such as potassium bisulfate, hydrochloride acid or sulfuric acid in the presence of a solvent such as ethyl acetate (EtOAc) or dichloromethane. The resulting free acid is subjected to lactonization by treating a solution of same in an inert organic solvent such as ethyl acetate or dichloromethane with trifluoroacetic (TFA) or hydrofluoric acid employing a molar ratio of acid:free acid of within the range of from about 0.1:1 to about 0.2:1, for a period of from about 16 to about 24 hours.

Lactone III is dissolved in, for example, methylene chloride or tetrahydrofuran, and then treated with amine base such as imidazole, triethylamine, ethyldiisopropylamine or N,N-dimethylaniline and then with a silyl chloride protecting agent (ProCl) such as tertiary-butyldimethylsilyl chloride, tertiary-butyldiphenylsilyl chloride, triethylsilyl chloride or phenyldimethylsilyl chloride, and an appropriate catalyst such as 4-(N,N-dimethylamino)pyridine (DMAP), for a period of from about 8 to about 24 hours, preferably from about 12 to about 16 hours, to form the protected compound IV. In carrying out the above reaction the amine base is employed in a molar ratio to the lactone III of within the range of from about 1:1 to about 1.2:1 and the silyl chloride protecting agent is employed in a molar ratio to lactone III of within the range of from about 1:1 to about 1.1:1.

The protected compound IV is then hydrogenated by treatment with hydrogen (for a period of from about 4 to about 24 hours) in the presence of a hydrogenation catalyst such as platinum on carbon, palladium on carbon or platinum oxide, and the crude reduction product is desilylated by treatment with hydrofluoric acid (for a period of from about 0.5 to about 1.5 hours) in the presence of an organic solvent such as acetonitrile under an inert atmosphere such as argon, employing a molar ratio of crude reaction product:HF of within the range of from about 1:2 to about 1:5, to form the compound V.

Compound V is then reduced by treating a solution of V in an inert organic solvent such as tetrahydrofuran, dichloromethane or toluene, with diisobutylaluminum hydride (DIBAL-H), under an inert atmosphere such as argon, at a temperature within the range of from about -80.degree. C. to about -40.degree. C., for a period of from about 0.5 to about 2 hours, to form a crude lactol which is suspended under an inert atmosphere such as argon in an inert organic solvent such as tetrahydrofuran, and treated with sodium borohydride and an alcohol solvent such as methanol or ethanol, at a temperature within the range of from about 0.degree. C. to about 25.degree. C., to form crude tetraol. The crude tetraol, with further purification, is dissolved in dry inert organic solvent such as dry dimethylformamide (DMF), under an inert atmosphere such as argon, and selectively silylated by treating with a base such as imidazole and the like as described above, silylating agent (ProCl), as described above, using the procedure as described hereinbefore, to form the silylated compound VI. Compound VI is then converted to the corresponding acetonide by treating with p-toluenesulfonic acid monohydrate (p-TsOH) in the presence of dry acetone for a period of from about 4 to about 16 hours, to form the acetonide compound VII.

Compound VII is then oxidized via a Dess-Martin periodinane by admixing a solution of Dess-Martin periodinane in an inert organic solvent such as methylene chloride, under an inert atmosphere such as argon, with t-butanol and a solution of VII in an inert organic solvent such as methylene chloride for a period of from about 0.5 to about 2 hours, employing a molar ratio of periodinane:VII of within the range of from about 1:1 to about 1.5:1. The crude product is purified and made to undergo base-catalyzed elimination by forming a solution of the purified product with an aromatic solvent such as toluene or benzene and treating the solution with diazobicycloundecane (DBU), for a period of from about 1 to about 2 hours, to form compound VIII. Compound VIII is dissolved in dry pyridine and is treated with a solution of OsO.sub.4 in dry pyridine under an inert atmosphere such as argon, employing a molar ratio of OsO.sub.4 :VIII of within the range of from about 1:1 to about 1.1:1, for a period of from about 1 to about 4 hours, to form IX.

To a solution of compound IX in dioxane, under an inert atmosphere such as argon, is added a solution of sodium periodate in water (employing a molar ratio of IX:periodate of from about 1:2 to about 1:2.5), the resulting reaction is allowed to proceed for a period of from about 12 to about 18 hours. The resulting crude product is taken up in a solvent such as diethyl ether, cooled and treated with etherial diazomethane to form an aldehyde which is dissolved in dry tetrahydrofuran, at a temperature of from about -10.degree. to about 0.degree. C., and treated under an inert atmosphere such as argon, with a reducing agent such as LiAl(Ot-C.sub.4 H.sub.9).sub.3 H, to form compound X.

Compound X is then reduced by treating a solution of X in dry organic solvent such as toluene, dichloromethane or tetrahydrofuran, with diisobutylaluminum hydride (DIBAL-H), in dry organic solvent such as toluene, under an inert atmosphere such as argon, at a temperature of from about -80.degree. to about -40.degree. C., for a period of from about 0.5 to about 2 hours, to form crude lactol which is subjected to a Wittig reaction as follows. A suspension of a triphenylphosphonium bromide of the structure A

(C.sub.6 H.sub.5).sub.3 P.sup..sym. CH.sub.2 R.sup.1 Br.sup..crclbar.(A)

in dry organic solvent such as toluene, or tetrahydrofuran, at a temperature of from about -20.degree. to about 0.degree. C., under an inert atmosphere such as argon, is treated with a solution of potassium t-amylate or potassium bis(trimethylsilyl)amide in dry organic solvent such as toluene, or tetrahydrofuran. After stirring the mixture for about 0.5 to about 2 hours, a solution of the above crude lactol in dry organic solvent such as toluene or tetrahydrofuran is reacted with the mixture, at a temperature of from about 0.degree. to about 25.degree. C., for a period of from about 1 to about 3 hours, employing a molar ratio of lactol:phosphonium compound A of within the range of from about 1:2 to about 1:4, to form alcohol XI. Alcohol XI is reduced by treating with hydrogen (for a period of from about 1 to about 2 hours) in the presence of a hydrogenation catalyst such as palladium on carbon, platinum on carbon or platinum oxide, and an alcohol solvent such as methanol or ethanol. The crude product is then acylated by treating same with an acylating agent of the structure B

R.sup.2 COCl B

employing a molar ratio of reduced alcohol:B of within the range of from about 1:1 to about 1:2 in the presence of base such as pyridine and 4-(N,N-dimethylamino)pyridine (DMAP), under an inert atmosphere such as argon, at a temperature of from about 0.degree. to about 25.degree. C., for a period of from about 8 to about 24 hours, to form ester XII.

Ester XII is made to undergo desilylation by treating a solution of XII in dry organic solvent such as tetrahydrofuran, under an inert atmosphere such as argon, with a desilylating agent such as (n--C.sub.4 H.sub.9).sub.4 NF, in an organic solvent such as tetrahydrofuran, for a period of from about 8 to about 24 hours, employing a molar ratio of XII: disilylating agent of from about 1:1 to about 1:3, to form alcohol XIII.

Compound XIII is then oxidized via Dess-Martin periodinane by admixing a solution of Dess-Martin periodinane in an inert organic solvent such as methylene chloride, under an inert atmosphere such as argon, with t-butanol and a solution of XIII in an inert organic solvent such as methylene chloride, for a period of from about 0.5 to about 2 hours, employing a molar ratio of periodinane:XIII of within the range of from about 1:1 to about 1.5:1. The crude aldehyde is taken up in an organic solvent such as t-butanol and 5% aqueous NaH.sub.2 PO.sub.4, and treated with oxidizing agent such as potassium permanganate, for a period of from about 5 to about 15 minutes, employing a molar ratio of crude aldehyde:oxidizing agent of from about 1:5 to about 1:10, to form crude acid which is esterified by treatment with etherial diazoalkane such as diazomethane, diazoethane, or phenyldiazomethane, to form the ester XIV.

Ester XIV is subjected to acetonide cleavage and lactonization by treating a solution of XIV, in a mixture of aqueous hydrofluoric acid and acetonitrile for a period of from about 4 to about 8 hours, to form the lactone of the invention IC.

The formula IC compound of the invention may be hydrolyzed by treating IC with aqueous alkali metal base to form the compound ID of the invention.

Referring to the Reaction Scheme II set out hereinbefore, compounds of formula IB (X is NR.sup.5) are prepared starting with alcohol XI which is reduced by treatment with hydrogen in the presence of a catalyst such as palladium on charcoal and an alcohol solvent such as methanol, to form XIA. XIA is mesylated by reacting XIA with methanesulfonyl chloride in the presence of triethylamine or other base such as diisopropylethylamine, in the presence of an inert organic solvent such as methylene chloride to form crude mesylate, followed by displacement with lithium or sodium azide by treating the mesylate with lithium or sodium azide in the presence of dimethylformamide at a temperature of from about 25.degree. to about 75.degree. C., for a period of from about 2 to about 8 hours, to form the azide compound XIB.

Azide XIB is then reduced by treatment with hydrogen in the presence of palladium on charcoal and alcohol solvent such as methanol or ethanol and the resulting compound is acylated by treatment with acylating agent B

R.sup.2 COCl B

employing a molar ratio of amine:B of within the range of from about 1:1 to about 1:3, in the presence of base such as pyridine and 4-(N,N-dimethylamino)pyridine (DMAP), under an inert atmosphere such as argon, at a temperature of from about 0.degree. to about 25.degree. C., for a period of from about 0.5 to about 2 hours, to form amide XIIA.

Amide XIIA may be used in place of ester XII in Reaction Scheme I to form compounds XIIIA, XIVA, IF and IG where R.sup.5 is H.

Compounds of the invention of formula I where X is NR.sup.5, and R.sup.5 is alkyl may be prepared by treating amide XIIA with a base such as sodium hydride, or potassium t-butoxide and an alkylhalide R.sup.5a -X (where R.sup.5a is alkyl and X is bromine or iodine) in a solvent such as tetrahydrofuran or dimethylfuramide, at a temperture of from about 25.degree. to about 50.degree. C., for a period of from about 2 to about 16 hours, employing a molar ratio of base:XIIA of from about 1:1 to about 1.1:1 and a molar ratio of alkyl halide:XIIA of from about 1:1 to about 3:1, to form amide XIIB.

Amide XIIB may be used in place of amide XII in Reaction Scheme I to form compounds XIIIA, XIVA, IF AND IG, where R.sup.5 is alkyl.

Compounds of the invention where R is lower alkyl may be prepared as follows.

Esters, preferably alkyl esters, of the carboxylic acids of formula IE or IH may be obtained by contacting the carboxylic acid of formula IE or IH with an appropriate alcohol, preferably in the presence of an acid catalyst, for example a mineral acid (such as hydrochloric acid or sulphuric acid), a Lewis acid (for example boron trifluoride) or an ion exchange resin. The solvent employed for this reaction is not critical, provided that it does not adversely affect the reaction: suitable solvents include benzene, chloroform, ethers and the like. Alternatively, the desired product may be obtained by contacting the carboxylic acid of formula IE or IH with a diazoalkane, in which the alkane moiety may be substituted or unsubstituted. This reaction is usually effected by contacting the acid with an ethereal solution of the diazoalkane. As a further alternative, the ester may be obtained by contacting a metal salt of the carboxylic acid of formula IE or IH with a halide, preferably an alkyl halide, in a suitable solvent: preferred solvents include dimethylformamide, tetrahydrofuran, dimethylsulfoxide and acetone. All of the reactions for producing esters are preferably effected at about ambient temperature, but, if required by the nature of the reaction system, the reactions may be conducted with heating.

Compound IE or IH of the invention is obtained by Careful acidification of an aqueous solution of compound ID or IG with an acid such as aqueous potassium bisulfate followed by extraction of IE or IH from the aqueous mixture with an organic solvent such as ethyl acetate, dichloromethane or chloroform. The organic extracts are then dried with MgSO.sub.4 or Na.sub.2 SO.sub.4, filtered and concentrated to provide IE or IH.

Compounds of the invention of formula I where R is lower alkyl may also be obtained by adding to a solution of compound IC or IF in an appropriate alcohol a slight molar excess of the corresponding alkoxide. The mixture is then diluted with an organic solvent such as ethyl acetate or chloroform and extracted with water. The organic portion is dried with MgSO.sub.4 or Na.sub.2 SO.sub.4, filtered and concentrated to provide lower alkyl ester of compounds of formula 1.

Alternatively, compounds of the invention of formula I where R is lower alkyl are obtained by solvolysis of the lactone IC or IF in the presence of an appropriate alcohol and an acid catalyst, which may be an inorganic acid such as hydrochloric acid or sulphuric acid, a Lewis acid such as boron trifluoride or an acidic ion-exchange resin. In the case of an inorganic acid or Lewis acid, isolation of the product ester involves neutralization and extraction followed by drying, filtering and concentrating. In the case of an ion exchange resin, simple filtration and concentration will provide the product ester.

The compounds of formula I of the invention will be formulated with a pharmaceutical vehicle or diluent. The pharmaceutical composition can be formulated in a classical manner utilizing solid or liquid vehicles or diluents and pharmaceutical additives of a type appropriate to the mode of desired administration. The compounds can be administered by an oral route, for example, in the form of tablets, capsules, granules or powders, or they can be administered by a parenteral route in the form of injectable preparations.

A typical capsule for oral administration contains active ingredients (25 mg), lactose (75 mg) and magnesium stearate (15 mg). The mixture is passed through a 60 mesh sieve and packed into a No. 1 gelatin capsule.

A typical injectable preparation is produced by asceptically placing 25 mg of a water soluble salt of sterile active ingredient into a vial, asceptically freeze-drying and sealing. For use, the contents of the vial are mixed with 2 ml of physiological saline, to produce an injectable preparation.

New intermediates in accordance with the present invention may be represented by the following formulae: ##STR38## where R.sup.5' CH.sub.2 OH or CO.sub.2 alkyl.

The compounds of the invention are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and inhibit cholesterol biosynthesis. Such compounds are useful in treating atherosclerosis to inhibit progression of disease, in treating hyperlipidemia to inhibit development of atherosclerosis, and in treating nephrotic hyperlipidemia. In addition, the compounds of the invention increase plasma high density lipoprotein cholesterol levels and lower plasma low density and intermediate density lipoprotein cholesterol levels.

As HMG CoA reductase inhibitors, the compounds of the invention may also be useful in inhibiting formation of gallstones and in treating tumors.

The compounds of the invention may also be employed in combination with an antihyperlipoproteinemic agent such as probucol and/or with one or more serum cholesterol lowering agents such as Lopid (gemfibrozil), bile acid sequestrants such as cholestyramine, colestipol, DEAE-Sephadex as well as clofibrate, nicotinic acid and its derivatives, neomycin, p-aminosalicyclic acid, lovastatin, pravastatin, visinolin (velostatin, symvastatin or sinvinolin) and the like, and/or one or more squalene synthetase inhibitors.

The above compounds to be employed in combination with the HMG CoA reductase inhibitor of the invention will be used in amounts as indicated in the Physicians' Desk Reference (PDR).

The compounds of this invention also have useful antifungal activities. For example, they may be used to control strains of Penicillium sp., Aspergillus niger, Cladosporium sp., Cochliobolus miyabeorus and Helminthosporium cynodnotis. For those utilities they are admixed with suitable formulating agents, powders, emulsifying agents or solvents such as aqueous ethanol and sprayed or dusted on the plants to be protected.

In addition, the compounds of the invention may be useful in elevating HDL-cholesterol while lowering levels of LDL-cholesterol and serum triglycerides, and for treating tumors.

The compounds of the invention prepared as described above are single, homochiral diastereomers. The compounds of the described absolute stereochemistry are preferred, but compounds with the opposite stereochemistry at one or more of the stereocenters are also within the scope of the present invention.

The compounds of the invention are inhibitors of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase and thus are useful in inhibiting cholesterol biosynthesis as demonstrated by the following tests.

1) Rat Hepatic HMG-CoA Reductase

Rat hepatic HMG-CoA reductase activity is measured using a modification of the method described by Edwards (Edwards, P. A., et al., J. Lipid Res. 20:40, 1979). Rat hepatic microsomes are used as a source of enzyme, and the enzyme activity is determined by measuring the conversion of the .sup.14 C-HMG-CoA substrate to .sup.14 C-mevalonic acid.

a. Preparation of Microsomes

Livers are removed from 2-4 cholestyramine-fed, decapitated, Sprague Dawley rats, and homogenized in phosphate buffer A (potassium phosphate, 0.04M, pH 7.2; KCl, 0.05M; sucrose, 0.1M; EDTA, 0.03M; aprotinin, 500 KI units/ml). The homogenate is spun at 16,000.times.g for 15 minutes at 4.degree. C. The supernatant is removed and recentrifuged under the same conditions a second time. The second 16,000.times.g supernatant is spun at 100,000.times.g for 70 minutes at 4.degree. C. Pelleted microsomes are resuspended in a minimum volume of buffer A (3-5 ml per liver), and