`
`849
`
`Notes
`
`3-Hydroxy-3-methylglutaryl-coenzyme A Reductase Inhibitors. 4.' Side Chain
`Ester Derivatives of Mevinolin
`
`W. F. Hoffman,*+ A. W. Alberts,* P. S. Anderson,' J. S. Chen,* R. L. Smith,? and A. K. Willardt*$
`
`Merck Sharp & Dohme Research Laboratories, West Point, Pennsylvania 19486, and Rahway, New Jersey 07065.
`Received July I , 1985
`
`Modification of the 2(S)-methylbutyryl moiety of mevinolm led to a series of side chain ester derivatives. A systematic
`exploration of the structure-activity relationships showed that the introduction of an additional aliphatic group
`on the carbon cy to the carbonyl group increased potency. This observation led to the synthesis of compound 16,
`which has about 2.5 times the intrinsic inhibitory activity of mevinolin.
`
`Scheme I
`
`3
`
`The novel fungal metabolites compactin (ML-236B)2p3
`(la) and mevinolin (MK-803, monacolin K)415 (lb) are
`potent inhibitors of cholesterol biosynthesis at the level
`of the rate-limiting enzyme 3-hydroxy-3-methylglutaryl-
`coenzyme A reductase [HMG-CoA reductase; mevalo-
`nate:NADP+ oxidoreductase (CoA acylating), EC 1.1.1.34].6
`Mevinolinic acid (2) , the dihydroxy acid form of the lactone
`lb, is the most potent inhibitor (Ki = 0.6 nM)4 reported
`to date and is an effective hypocholesterolemic agent in
`several animal species and man.4,7 Since HMG-CoA re-
`ductase6 catalyses the rate-limiting step in cholesterogen-
`esis and hypercholesterolemia is a known primary risk
`factor8q9 for coronary heart disease (the major cause of
`death in Western countries), it was deemed important to
`delineate the structural features of mevinolin responsible
`for its HMG-CoA reductase inhibitory activity. In this
`paper, the first of a series describing studies on the
`structural modification of mevinolin, we describe the re-
`sults of modifying the 2(S)-methylbutyryl moiety, some
`of which led to side chain ester derivatives with enhanced
`potencies.
`
`UCH3
`
`512, R = (CH3),CH
`b, R = C&CHz
`C. R =(CH3CHz&C
`"4a (method A): (CH3)&HCOC1, 4-DMAP, pyridine, 20 "C, 18
`h. 4b (method B): PhCH2C02H, dicyclohexylcarbodiimide, 4-
`pyrrolidinopyridine, CHzC12, 20 "C, 18 h. 4c (method C): (CH3C-
`H,),CCOCl, 4-pyrrolidinopyridine, pyridine, 100 "C, 12 h. *Three
`equivalents of Bu,N+F-.3H20, 4 equiv of HOAc, THF, 20 "C, 18 h.
`
`2
`
`of the hindered axial alcohol 3 with isobutyryl chloride in
`pyridine containing 4-(dimethy1amino)pyridine (DMAP)
`
`la, R = H
`b, RmCH3
`
`Chemistry. The compounds prepared for this study
`are listed in Table I. Their syntheses from the corre-
`sponding silyl ether 31° are shown in Scheme I. Acylation
`
`t West Point, PA.
`Rahway, NJ.
`5 Present address: Stuart Pharmaceuticals, Division of IC1
`Americas, Wilmington, DE 19897.
`(1) Part 3: Stokker, G. E.; Alberts, A. W.; Anderson, P. S.; Cragoe,
`E. J., Jr.; Deana, A. A.; Gilfillan, J. L.; Hirshfield, J.; Holtz, W.
`J.; Hoffman, W. F.; Huff, J. W.; Lee, T. J.; Novello, F. C.;
`Prugh, J. D.; Smith, R. L.; Willard, A. K. J. Med. Chem. 1986,
`29, 170.
`(2) Brown, A. G.; Smale, T. C.; King, T. J.; Hasenkamp, R.;
`Thompson, R. H. J. Chem. Soc., Perkin Trans. 1 1976, 1165.
`(3) Endo, A.; Kuroda, M.; Tsujita, Y. J. Antibiot. 1976, 29, 1346.
`
`(4) Alberts, A. W.; Chen, J.; Kuron, G.; Hunt, V.; Huff, J.; Hoff-
`man, C.; Rothrock, J.; Lopez, M.; Joshua, H.; Harris, E.;
`Patchett, A.; Monaghan, R.; Currie, S.; Stapley, E.; Albers-
`Schonberg, G.; Hensens, 0.; Hirshfield, J.; Hoogsteen, K.;
`Liesch, J.; Springer, J. Proc. Natl. Acad. Sci. U.S.A. 1980, 77,
`3957.
`(5) Endo, A. J. Antibiot. 1980, 33, 334.
`(6) Rodwell, V. W.; Nordstrom, J. L.; Mitschelen, J. J. Adu. Lipid
`Res. 1976, 14, 1.
`(7) (a) Tobert, J. A.; Hitzenberger, G.; Kukovetz, W. R.; Holmes,
`I. B.; Jones, K. H. Atherosclerosis 1982,41, 61. (b) Tobert, J.
`A.; Bell, G. D.; Birtwell, J.; James, I.; Kukovetz, W. R.; Pryor,
`J. S.; Buntinx, A.; Holmes, I. B.; Chao, Y.-S.; Bolognese, J. A.
`J. Clin. Znuest. 1982, 69, 913.
`(8) Kannel, W. B.; Castelli, W. P.; Gordon, T.; McNamara, P. M.
`Ann. Intern. Med. 1971, 74, 1.
`(9) Stamler J. Arch. Surg. 1978, 113, 21.
`
`0022-2623/86/1829-0849$01.50/0 0 1986 American Chemical Society
`
`NCI Exhibit 2025
`Page 1 of 4
`
`
`
`850 Journal of Medicinal Chemistry, 1986, Vol. 29, No. 5
`
`Notes
`
`Table I. Effects of Modification of the Side Chain Ester Moiety of Mevinolin Howo
`
`no.
`l b
`
`6
`7
`8
`9
`5a
`10
`11
`
`12
`
`13
`14
`
`15
`16
`17
`5c
`18
`19
`
`20
`
`5b
`
`21
`
`R'
`
`recryst solvent
`
`mp, O C
`
`formula"
`
`methodb
`
`H CH,
`\.?
`CHi,CH2C
`
`n-C4H9C1
`ether/ hexane
`chromat CHzClz/acetone (4/1)
`chromat CH2C12/acetone (9/1)
`CH,CN/HZO
`ether
`prep HPLC Zorbax ODS
`CH3CN/H20 (45/55)
`prep HPLC Zorbax ODS
`CH,CN/H20 (45/55)
`chromat CH2C12/acetone (4/1)
`prep HPLC Altex C,
`
`153-156
`116-119
`semisolid
`semisolid
`144- 147
`119-123
`113-118
`
`116-119
`
`110-1 13
`126-128
`
`CH&N/HZO (45/55)
`n-C4H9C1
`n-C4H9C1/ hexane
`n-C4HgC1/ hexane
`CH,CN/H20
`ether/ hexane
`cyclohexane
`
`167.5-170.5 C24H3605
`135-138
`C25H3805
`111-113
`C26H4005
`129-132
`C27H4205
`81-83
`C28H4405
`155-158
`
`C30H4205'1
`
`/ 20C6H12
`
`chromat ether/CHzClz (1/1)
`
`119.5-120.5 CZ6H3,FO5
`
`CHBCN/H,O
`
`n-CdH9CI
`
`109-112
`
`C27H3405
`
`120-1 22
`
`C26H3206'1/4C4H9C1
`
`A
`B
`A
`B
`A
`A
`B
`
`B
`
`B
`A
`
`A
`Cf
`C
`C
`C
`A8
`
`A
`
`B
`
`A
`
`IC50,c
`nM
`2.2
`
`relative
`potencyd
`254
`
`269
`38.6
`8.7
`295
`7.7
`5.4
`27.3
`
`2.9
`
`3.5
`2.2
`
`2.7
`0.9
`1.4
`1.4
`1.9
`3.8
`
`37
`
`19
`
`83
`
`2.1
`14
`64
`1.9
`72
`103
`20
`
`187
`
`157
`254
`
`209
`622
`394
`391
`294
`147
`
`15
`
`29
`
`6.8
`
`'See Experimental
`"Analytical results are within *0.4% of the theoretical values. bSee Experimental Section for details of methods A-C.
`Section for protocol. dFor estimation of relative inhibitory potencies, compactin was assigned a value of 100 and the IC,, value of the test
`compound was compared with that of compactin determined simultaneously. 'C, H analysis was not obtained. The 360-,Hz NMR was in
`full agreement with the structure. IThe acylation was run at 100 "C for 4 h. gThe acylation was run at ambient temperature for 5 days.
`
`as a catalyst at ambient temperature for 18 h (method A)
`resulted in quantitative conversion to the ester 4a. An
`alternative acylation procedure (method B) is demon-
`strated by the preparation of the phenylacetic ester 4b via
`treatment of a CH2Cl2 solution of the alcohol 3 with
`phenylacetic acid and dicyclohexylcarbodiimide in the
`presence of 4-pyrrolidinopyridine. This procedure was also
`used for the preparation of 7, since the attempted synthesis
`of 7 by method A failed to provide any of the desired ester.
`However, method B could not be used to prepare the ad-
`amantyl derivative 19 as no acylation occurred after 3 days.
`The extremely hindered esters such as the diethylbutyric
`ester 4c could not be prepared by methods A or B but
`required more vigorous acylation conditions. Heating a
`pyridine solution of the alcohol 3 and the diethylbutyryl
`chloride at 100 OC for 12 h in the presence of DMAP or
`4-pyrrolidinopyridine as a catalyst provided the ester 4c
`(method C). In this instance, the overall yield was only
`40% because of byproducts resulting from the elimination
`of the 0-silyloxy ether at elevated temperatures.
`As noted previously,1° attempted deprotection of the silyl
`
`(10) Willard, A. K.; Smith, R. L. J. Labelled Compd. Radiopharrn.
`1982, 19, 337.
`
`ethers 4 with tetrabutylammonium fluoride in THF caused
`rapid and extensive destruction of the lactone ring.'l
`Attenuation of the offending basicity of fluoride by ad-
`dition of acetic acid permitted clean unmasking of the
`0-hydroxy lactones 5.
`Biological Results and Discussion
`The compounds listed in Table I were converted to their
`ring-opened sodium dihydroxy carboxylate salts and were
`evaluated for their ability to inhibit solubilized, purified
`rat liver HMG-CoA reductase. The elimination of
`branching in the side chain ester moiety of lb provided
`compounds 6-9, which had diminished inhibitory activities.
`The removal of the terminal methyl from the 2-methyl-
`butyryl moiety gave 5a, which was about one-third as
`
`(11) Treatment of mevinolin (lb) under the same reaction condi-
`tions (Le., 3 equiv of Bu4N+F-.3H20, THF, 20 "C) for 2 h
`followed by careful acidification (1 N HC1, slight excess) af-
`forded mevinolinic acid (2) exclusively. Hence, although both
`p-silyloxy lactones 4 and @-hydroxy lactone 1 are sensitive to
`the basicity of fluoride under typical Corey condition^,'^ their
`relative propensities toward 1,Z-diaxial elimination differ
`markedly.
`
`NCI Exhibit 2025
`Page 2 of 4
`
`
`
`Notes
`
`potent as lb. When the a-methyl group was moved further
`from the carbonyl group (i.e., to the @carbon (lo)), activity
`was diminished by 50%. The introduction of unsaturation
`into the isopentyl moiety of 10 to provide 11 lowered the
`intrinsic inhibitory activity. However, when the double
`bond was moved to the B and y carbons, activity was in-
`creased. Replacing the terminal methyl of 10 with a tri-
`fluoromethyl group 13 also increased the activity. Inter-
`estingly, stereochemistry at the carbon a to the carbonyl
`group is not critical as l b and its diastereomer 14 are
`equally potent. The introduction of an additional methyl
`group on the carbon a to the carbonyl group to give 16
`increased the potency about 2.5-fold. Increasing the length
`of the substituents on the CY carbon provided esters 17,5c,
`and 18, which were less potent than 16 but more potent
`than lb. Replacement of the bulky side chain of 16 with
`the more compact adamantyl moiety (19) ablated activity
`as did conversion to aromatic esters 20, 5b, and 21. No
`statistically significant correlation could be made between
`log PIz or volume13 and log (relative potency) for the 20
`side chain ester derivatives in Table I.
`Analysis of the intrinsic inhibitory activities of these
`compounds suggests the following: (a) the stereochemistry
`of the side chain ester moiety is not important for inhi-
`bitory binding to HMG-CoA reductase; (b) the spacial
`requirements of the acyl moiety are compatible with com-
`pact, branched-chain aliphatic acyl groups; and (c) addi-
`tional branching at the a carbon of the acyl moiety in-
`creases potency. Further modifications of the side chain
`ester moiety as well as other portions of the mevinolin
`structure along with in vivo testing results will be described
`in subsequent papers from these laboratories.
`Experimental Section
`Melting points were determined on a Thomas-Hoover capillary
`melting point apparatus and are uncorrected. Proton NMR
`spectra were recorded in CDC13, unless noted otherwise, on either
`a Varian EM-390, XL-300, or NT-360 spectrometer. Chemical
`shifts are reported in parts per million relative to Me4Si as the
`internal standard. Elemental analysis for carbon, hydrogen, and
`nitrogen were determined with a Perkin-Elmer Model 240 ele-
`mental analyzer and are within &0.4% of theory unless noted
`otherwise. Optical rotations were determined with a Perkin-Elmer
`Model 141 polarimeter. All starting materials were commercially
`available unless indicated otherwise.
`[1S-[ la,3a,7@,8@(2S *,4S *)8a@]]-8-[2-[4-[[(1,l-Dimethyl-
`et hyl)dimethylsilyl]oxy]tetrahydro-6-oxo-2H-pyran-2-y1]-
`ethyl] - 1,2,3,7,8,8a-hexahydr0-3,7-dimet hyl- 1 -napht halen yl
`2-Methylpropionate (4a) (Method A). Isobutyl chloride (0.49
`g, 4.6 mmol) was added over 2 min to a stirred solution of the
`alcohol 3'' (0.5 g, 1.15 mmol) and DMAP (50 mg) in dry pyridine
`(5 mL) at 0 "C under a nitrogen atmosphere. The reaction mixture
`was stirred at 0 OC for 1 h and then at ambient temperature for
`18 h. The reaction mixture was diluted with ether (100 mL) and
`washed with 2% aqueous HCl(3 X 25 mL), saturated NaHC03
`solution (25 mL), and brine (2 X 25 mL). After drying (MgS04)
`and filtration, the solution was evaporated to give crude 4a as
`a viscous yellow oil. The oil was chromatographed on a silica gel
`(230-400 mesh) column. Elution with CHzC12-acetone (32.3:1,
`v/v, 200 mL) provided a forerun, which was discarded. Continued
`elution with the same eluant (200 mL) gave the ester 4a (0.58 g)
`as a pale yellow oil. NMR 6 0.09 (6 H, s), 0.88 (9 H, s), 1.13 (6
`H, d, J = 6 Hz), 4.32 (H, m), 4.63 (H, m), 5.34 (H, m), 5.54 (H,
`m), 5.78 (H, dd, J = 6, 10 Hz), 6.03 (H, d, J = 10 Hz).
`[IS-[ la,3a,7@,8@(2S *,45*),8a@]]-1,2,3,7,8,8a-Hexahydro-
`3,7-dimethyl-8-[2-( tetrahydro-4- hydroxy-6-oxo-2H-pyran-2-
`yl)ethyl]-l-naphthalenyl2-Methylpropionate (5a). A solution
`of 4a (0.58 g, 1.15 mmol) in THF (10 mL) was added to a mag-
`netically stirred solution of acetic acid (0.341 g, 4.8 mmol) and
`
`(12) Smith, G. M., in house program.
`(13) Pomona Medchem Project, Pomona College, Claremont, CA.
`
`Journal of Medicinal Chemistry, 1986, Vol. 29, No. 5 851
`
`Bu4N+F-.3H20 (1.13 g, 3.6 mmol) in THF (10 mL), and the
`reaction was stirred 18 h at ambient temperature. The reaction
`mixture was diluted with ether (100 mL) and washed successively
`with 2% aqueous HC1, HzO (25 mL), and brine (2 X 25 mL). After
`drying (MgS04) and filtration, the solution was evaporated to
`provide 5a as a pale yellow solid. The solid was chromatographed
`on a silica gel (230-400 mesh) column. Elution with CHzClZ-
`acetone (4:1, v/v, 300 mL) provided a forerun, which was dis-
`carded. continued elution with the same eluant (280 mL) gave
`the ester 5a. Recrystallization of the solid provided an analytical
`sample as colorless needles. NMR 6 0.88 (3 H, d, J = 7 Hz), 1.08
`(3 H, d, J = 7 Hz), 1.13 (6 H, d, J = 6 Hz), 2.67 (2 H, m), 4.30
`(H, m), 4.55 (H, m), 5.30 (H, m), 5.50 (H, m), 5.70 (H, dd, J =
`6, 10 Hz), 5.95 (H, d, J = 10 Hz).
`[IS-[ la,3a,7@,8@(2S *,4S *),8a@]]-8-[2-[4-[ [ (1,l-Dimethyl-
`ethyl)dimethylsilyl]oxy]tetrahydro-6-oxo-2H-pyran-2-yl]-
`ethyl]-1,2,3,7,8,8a-hexahydro-3,7-dimethyl-l-naphthalenyl
`Benzeneacetate (4b) (Method B). A solution of the alcohol
`3 (434 mg, 1.0 mmol), benzeneacetic acid (204 mg, 1.5 mmol) and
`N,"-dicyclohexylcarbodiimide
`(309 mg, 1.5 mmol) in CHzClz (10
`mL) was treated with 4-pyrrolidinopyridine (22 mg, 0.15 mmol)
`and stirred at ambient temperature under a nitrogen atmosphere.
`After 3 days the solvent was removed in vacuo and the residue
`was suspended in ether (25 mL) and filtered. Evaporation of the
`filtrate provided a viscous oil, which was chromatographed on
`silica gel (230-400 mesh). Elution with ether-hexane (l:l, v/v,
`60 mL) gave a forerun, which was discarded. Continued elution
`with the same eluant (60 mL) provided the ester 4b as a colorless,
`viscous oil (460 mg, 83%). NMR 6 0.10 (6 H, s), 0.90 (9 H, s),
`3.58 (2 H, s), 4.23 (H, m), 4.43 (H, m), 5.34 (H, m), 5.57 (€3, m),
`5.77 (H, dd, J = 6, 10 Hz), 6.03 (H, d, J = 10 Hz), 7.30 ( 5 H, br
`9).
`[ 15 -[ la,3a,7,!?,8,!?( 2 5 *,45 *),Sa@]]-l,2,3,7,8,8a-Hexahydro-
`3,7-dimethyl-8-[ 2- (tetrahydro-4-hydroxy-6-oxo-2 H-pyran-2-
`yl)ethyl]-1-naphthalenyl Benzeneacetate (5b). This product
`was prepared analogously to 5a, starting with 4b (460 mg, 0.83
`mmol) and purified by chromatography and recrystallization.
`NMR 6 0.83 (3 H, d, J = 7 Hz), 1.04 (3 H, d, J = 7 Hz), 3.58 (2
`H, s), 4.10-4.60 (2 H, br m), 5.36 (H, m), 5.57 (H, m), 5.78 (H,
`dd, J = 6, 10 Hz), 6.03 (H, d, J = 10 Hz), 7.33 (5 H, br s).
`[ 1 s - [ la,3a,7@,8@( 2 5 *,4S *),Sa,!?]]-S-[ 2-[ 4-[ [ ( 1,l-Dimethyl-
`ethyl)dimethylsilyl]oxy]tetrahydro-6-oxo-2H -pyran-Z-yl]-
`ethyl]-1,2,3,7,8,8a-hexahydro-3,7-dimethyl-l-naphthalenyl
`2,2-Diethylbutanoate (4c) (Method C). 2,2-Diethylbutyryl
`chloride (18.8 g, 115 mmol) was added to a magnetically stirred
`solution of the alcohol 3 (12.5 g, 28.7 mmol) and 4-pyrrolidino-
`pyridine (0.425 g, 2.87 mmol) in dry pyridine (100 mL), heated
`at 100 O C . The solution was stirred under a Nz atmosphere for
`12 h, cooled to ambient temperature, and added to ether (300 mL).
`The ethereal mixture was washed with 3 N HC1 (3 X 100 mL)
`and brine (4 X 100 mL) and dried (MgS04). After filtration and
`evaporation the crude product was chromatographed on a column
`of silica gel (70-230 mesh, 1 kg). Elution with ether-hexane (l:l,
`v/v, 3500 mL) provided a forerun, which was discarded. Con-
`tinued elution with the same eluant gave the ester 4c as a yellow
`oil (6.5 g, 40%). NMR 6 0.08 (6 H, s), 0.90 (9 H, s), 2.59 (2 H,
`d, J = 4 Hz), 4.32 (H, m), 4.63 (H, m), 5.52 (2 H, m), 5.80 (H, dd,
`J = 6, 10 Hz), 6.07 (H, d, J = 10 Hz).
`[IS-[ la,3a,7@,8@(2S *,4S *),8a@]]-1,2,3,7,8,8a-Hexahydro-
`3,7-dimethyl-8-[2-( tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-
`yl)ethyl]-1-naphthalenyl 2,2-Diethylbutyrate (5c). This
`compound was prepared analogously to 5a, starting with 4c (6.4
`g, 11.5 mmol) and purified by chromatography and recrystalli-
`zation. NMR 6 0.76 (9 H, t, J = 7 Hz), 0.83 (3 H, d, J = 7 Hz),
`1.09 (3 H, d, J = 7 Hz), 4.38 (H, m), 4.61 (H, m), 5.49 (2 €3, m),
`5.79 (H, dd, J = 10, 7 Hz), 6.00 (H, d, J = 10 Hz).
`2,2-Diethylpentanoic acid (22) was prepared by the general
`method of Pfeffer et al.15 n-Propyl bromide (5.4 g, 0.044 mol) was
`rapidly added at 0 OC to the dianion of 2-ethylbutanoic acid (5.1
`g, 0.044 mol) prepared in THF solution, and the reaction was
`stirred for 3 h at ambient temperature. Neutralization of the
`
`(14) Corey, E. J.; Venkateswarlu, A. J. Am. Chem. SOC. 1972, 94,
`6190.
`(15) Pfeffer, P. E.; Silbert, L. S.; Chirinko, J. M., Jr. J. Org. Chem.
`1972, 37, 451.
`
`NCI Exhibit 2025
`Page 3 of 4
`
`
`
`852
`
`J . Med. Chem. 1986,29, 852-855
`
`reaction by the addition of 10% HCl (100 mL) at 0 "C gave a
`mixture, which was extracted into petroleum ether (2 X 250 mL).
`The organic extracts were combined, washed with saturated brine
`(4 x 50 mL), dried (MgSO,), and evaporated to provide a liquid
`('7.4 g), which was distilled to give 22; bp 133-134 "C (20 mm)
`(5.2 g, 75%). NMR 6 0.70-1.00 (9 H, m), 1.03-1.37 (2 H, m),
`1.40-1.77 (6 H, m).
`The following acid chlorides were prepared by heating the acid
`and 2 equiv of thionyl chloride at 100 "C for 2 h and purified by
`distillation.
`2,2-Dimethylbutyryl chloride: bp 130-134 "C; yield 76%;
`NMR 6 0.83 (3 H, t, J = 7 Hz), 1.20 (6 H, s), 1.60 (2 H, q, J =
`5 Hz).
`2-Ethyl-2-methylbutyryl chloride: bp 155-158 "C; yield
`61%; NMR 6 0.90 (6 H, t, J = 7 Hz), 1.20 (3 H, s), 1.43-1.97 (4
`H, m).
`2,2-Diethylbutyryl chloride: bp 65-66 "C (20 mm); yield
`90%; NMR 6 0.83 (9 H, t, J = 7 Hz), 1.70 (6 H, t, J = 7 Hz).
`2,2-Diethylpentanoyl chloride: bp 80-81 "C (20 mm); yield
`92%; NMR 0.73-1.00 (9 H, m), 1.10-1.43 (2 H, m), 1.53-1.87 (6
`H, m).
`
`Isolation of HMG-CoA reductase was carried out as pre-
`viously described.16
`HMG-CoA Reductase Inhibition Assay. IC,, values were
`determined with use of five levels of each inhibitor in the assay
`slightly modified from that previously described!
`In the revised
`protocol, enzyme was incubated for 5 min with inhibitor and
`NADPH prior to initiating the reaction with [14C]HMG-CoA (12.5
`wM, 5.9 pCi/pmol). IC,, values were calculated from percent
`inhibitions.
`Acknowledgment. We are indebted to Drs. R. F.
`Hirschmann and E. H. Cordes for their encouragement
`throughout the course of this investigation, to Dr. W. C.
`Randall and staff for analytical support, to Dr. D. W.
`Cochran for NMR spectra, and to M. Z. Banker for man-
`uscript preparation.
`
`(16) Stokker, G. E.; Hoffman, W. F.; Alberts, A. W.; Cragoe, E. J.,
`Jr.; Deana, A. A.; Gilfillan, J. L.; Huff, J. W.; Novello, F. C.;
`Prugh, J. D.; Smith, R. L.; Willard, A. K. J. Med. Chem. 1985,
`28, 347.
`
`3-Hydroxy-3-methylglutaryl-coenzyme A Reductase Inhibitors. 5. 6-(Fluoren-9-y1)-
`and 6-(Fluoren-9-ylidenyl)-3,5-dihydroxyhexanoic Acids and Their Lactone
`Derivatives
`
`G. E. Stokker,*+ A. W. Alberts,l J. L. Gilfillan,t J. W. Huff,$ and R. L. Smitht
`
`Merck Sharp & Dohme Research Laboratories, West Point, Pennsylvania 19486, and Rahway, New Jersey 07065.
`Received July 26, 1985
`
`A limited study was conducted to determine the biological consequences of rendering the phenyl rings of the previously
`reported' 7-(3,5-disubstituted [ l,l'-biphenyl]-2-yl)-3,5-dihydroxy-6-heptenoic acids coplanar. Such constraint
`substantially diminished intrinsic HMG-CoA reductase inhibitory activity.
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`In a previous paper' on HMG-CoA reductase inhibitors,
`we reported the syntheses and biological properties of a
`series of 7-(3,5disubstituted [ l,l'-biphenyl]-2-yl)-3,5-di-
`hydroxy-6-heptenoic (and heptanoic) acids and their 6-
`lactones. In this paper, we describe the syntheses and
`biological consequences of rendering the two phenyl groups
`of the 1,l'-biphenyl fragment coplanar. The rationale for
`such a study is the observation that the intrinsic HMG-
`
`fluor- of greater than that is slightly of unsubstituted CoA enylidene reductase inhibitory 1 (from part 112 potency
`
`
`
`
`
`
`
`unsubstituted biphenyl 2 (from part 2).3 From those
`substituted biphenyl compounds in part 3 of this series,l
`compounds 3-5 were chosen for determining the effects
`of these constraints. The inherent difficulty in elaborating
`the dichlorofluorenylidene compound corresponding to
`biphenyl 3 compelled us to prepare the analogous dimethyl
`
`CI
`
`3
`
`CH3
`4
`
`* Merck Sharp & Dohme, Rahway, NJ.
`Merck Sharp & Dohme, West Point, PA.
`(1) Stokker, G. E.; Alberts, A. W.; Anderson, P. S.; Cragoe, E. J.
`Jr.; Deana, A. A.; Gilfillan, J. L.; Hirshfield, J.; Holtz, W. J.;
`Hoffman, W. F.; Huff, J. W.; Lee, T. J.; Novello, F. C.; Prugh,
`J. D.; Rooney, C. S.; Smith, R. L.; Willard, A. K. J. Med. Chem.
`1986, 29, 170.
`(2) Stokker, G. E.; Hoffman, W. F.; Alberts, A. W.; Cragoe, E. J.,
`Jr.; Deana, A. A.; Gilfillan, J. L.; Huff, J. W.; Novello, F. C.;
`Prugh, J. D.; Smith, R. L.; Willard, A. K. J. Med. Chem. 1985,
`28, 347.
`compound (8). We showed previ~usly'~~ that analogous
`
`(3) Hoffman, W. F.; Alberts, A. W.; Cragoe, E. J., Jr.; Deana, A.
`methyl-for-chlorine replacement on the central phenyl ring
`A.; Evans, B. E.; Gilfillan, J. L.; Gould, N. P.; Huff, J. W.;
`produces little, if any, lowering of intrinsic inhibitory po-
`Novello, F. C.; Prueh. J. D.: Rittle. K. E.: Smith. R. L.: Stokker.
`tency.
`G. E.; Willard, A.-K. J. Med. Chem. 1986, 29, 159.
`0022-2623/86/1829-0852$01.50/0 0 1986 American Chemical Society
`
`CI
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`5
`
`NCI Exhibit 2025
`Page 4 of 4