J. Med. Chem. 1985, 28, 347-358
`
`347
`
`3-Hydroxy-3-rnethylglutaryl-coenzyme A Reductaae Inhibitors. 1. Structural
`Modification of 5-Substituted 3,5-Dihydroxypentanoic Acids and Their Lactone
`Derivatives
`
`G. E. Stokker,“ W. F. Hoffman," A. W. Alberta,‘ E. J. Cragoe, Jr.,' A. A. Deana,’ J. L. Gilflllan,‘ J. W. Huff,‘
`F. C. Novella,’ J. D. Prugh,' R. L. Smith,‘ and A. K. Willard”
`
`Merck Sharp & Dohme Research Laboratories, West Point, Pennsylvania 19486, and Rahway, New Jersey 07065.
`Received June 21, 1984
`
`A series of 5-substituted 3.5-dihydroxypentanoic acids and their derivatives have been prepared and tested for inhibitirm
`of HMG-CoA reductase in vitro. In general, unless a carboxylate anion can be formed and the hydroxy groups remain
`unsubstituted in an erythro relationship, inhibitory activity is greatly reduced. Furthermore, only one snantiomer
`of the ring-opened form of lactone 8a(-.t) possesses the activity displayed by the racemate. Insertion of a bridging
`unit other than ethyl or (E)-ethenyl between the 5-carbinol moiety and an appropriate lipophilic moiety (e.g.,
`2.4-dichlorophenyl) attenuates activity.
`
`Formation of the atheromatous plaque or atheroma is
`accompanied by the localized deposition of plasma lipids.
`primarily cholesteryl esters, in the intima of the arterial
`wall.“ Growth of the atheroma eventually leads to con-
`striction of the coronary arterial lumen and ultimately
`results in atherosclerosis and coronary heart disease (CH-
`D), the major cause of death and disability in Western
`countries. These observations, coupled with the compelling
`epidemiological evidence implicating hypercholesterolemia
`as a primary risk factor for CHD.3-‘ have stimulated re-
`search on the development of therapeutic agents for pre-
`venting and treating atherosclerosis based on the attenu-
`ation of plasma cholesterol levels.‘ The results of the
`recently completed Lipid Research Clinics Coronary
`Primary Prevention Trial (LRC-CPP'I‘)° provide strong
`support for the basis of this approach. The LRC-CPPT
`clearly demonstrated that reduction of low-density lipo
`protein cholesterol (LDL-C) through dietary modification
`and treatment with the bile acid sequesterant cholestyr-
`amine. either alone or in combination, diminished the
`incidence of CHD morbidity and mortality in hypercho-
`lesterolemic men at high risk for CHD. Nevertheless, the
`reduction of dietary cholesterol and saturated fat intake
`and the use of bile acid sequesterants often fail to lower
`elevated plasma LDL-C levels to the desired extent, par-
`3_'<‘:}\1Il)a§ly in patients with familial hypercholesterolemia
`An attractive and potentially more efficacious way to
`lower plasma cholesterol levels would be to control de novo
`choleaterogenesis by selectively inhibiting an early bio-
`synthetic step. The highly functionalized fungal metab-
`olites compactin (ML-236B, CS-500)’ and mevinolin
`(MK-803)’ are potent inhibitors of cholesterol biosynthesis
`at the level of the major rate-limiting enzyme 3-hydroxy-
`3-methylglutaryl-coenzyme A reductase [HMG-CoA re-
`ductase; mevalonate:NADP* oxidoreductase (CoA acy-
`latins). EC 1.1.l.34],‘° which catalyzes the conversion of
`HMG-CoA to mevalonic acid (eq 1).
`Indeed, mevinolinic
`CH3
`EH3
`HO 5
`=_
`
`H
`
`C02" nus-coa uauclen
`0
`nova
`
`C02“
`OH
`
`U)
`
`Sc“
`NMG-COA
`
`
`mevalonic acid
`
`‘Merck Sharp 8: Dohme, West Point. PA.
`‘Merck Sharp dz Dohme, Rahway. NJ.
`‘Present address: Stuart Pharmaceuticals. Division of 1C!
`Americas, Wilmington, DE 19897.
`
`acid (1), the dihydroxy acid form of mevinolin, is the most
`potent HMG-CoA reductase inhibitor (K. I 0.6 nM) re-
`ported to date.’ Of even greater interest are the findings
`that compsctln“-" and mevino1in°"° are highly etfective
`hypocholeeterolemic agents in several animal species and
`man. Subsequent to the first reports disclosing the
`structure“ and biological activity’ of compactin, a series
`of studies directed toward the development of structurally
`simplified HMG—CoA reductase inhibitors were initiated
`in these Laboratories. Described in this paper are the
`results of our
`study,“ which served to delineate key
`
`
`(6)
`
`(1) Ross, R. Annu. Rev. Med. 1919, 80, 1.
`(2) Fuator, V. Scand. J. Haamatal. 1081, 27 (Suppl. 38), 1.
`(3) US. Department of Health and Human Services, National
`Iratitutes of Health, National Heart, Lung, and Blood Insti-
`tute, “Arterioscleroeis“, Vol. 1 and 9. NIH Publication No.
`81-2034 and 81-2035, U.S. G.P.O., Washington, DC, 1981.
`(4) Hamburg, D. A.; Elliott, G. R. Arteriosclerolie 1982, 2, 357.
`(5) Prugh, J. D.; Rooney, C. S.; Smith, R. 1.. Annu. Rep. Med.
`Chem. i983, l8, 161.
`(a) LRC-CPPT, J. Am. Med. Assoc. I984, 251. 351. (b) I..RC-
`CPPT, Ibid. I984, 251, 365.
`(7) Havel, R. J.; Kane, J. P. Annu. Rev. Med. 1982, 33, 417.
`(8) Endo, A.; Kurods. M.: Tsuiits, Y.J. Antibiot. 1978 29, 1343.
`(9) Alberta, A. W.; Chen, J.; Kuron, G.; Hunt, V.; Huff, J.; Hoff-
`man. C.; Rothrock. J.; Lopez, M.: Joshua, H.; Harris, 13.;
`Patchett, A.; Monaghan, R.; Currie, S.; Stapley, E.; Alban-
`Schonberg, G.; Hensens, 0.-, Hirshfield, J.; l-loogstsen. K.;
`Liesch, J.; Springer, J. Proc. Natl. Accd. Sci. U.S.A. 1980, 77,
`3957.
`(10) Rodwsll. V. W.; Nordstrom, J. L.; Mitschelen, J. J. Adv. Lipid
`Res. 1976, 14, 1.
`(a) Teujita, Y.; Kuroda, M; Tanzawa, K.; Kitano, N.; Bndo. A.
`Atherosclerosis (Shannon,Irel.) 1978, 32, W7. (b) Kuroda, M.:
`Tsujita, Y.; Tanzawa, K.; Endo. A. Lipids 1979, 14, 585.
`(12) (a) Yamarnoto, A.; Sudo, H.; Endo, A. Atherosclerosis (Shan-
`non, Irel.) 1980. 35. 259.
`(b) Mabuchi, H.; Haba. T.; Tstami.
`R.; Miyamoto. S.; Sakai, Y.; Wakasugi, T.; Watanabe. A.;
`Koizumi, J.; Takeda, R. N. Engl. J. Med. 1931, .905, as.
`(a) Tobert. J. A.; Hitzenberger, G.: Kulrovstz, W. R.; Holmes,
`1. B.; Jones, K. H. Atherosclerosis (Shannon. Irel.) 1982, 41.
`61.
`(b) Tobert, J. A.; Bell, G. D.; Birtwoll, J.; James, 1.; Ku-
`kovetz, W. R.; Pryor, J. S.; Buntinx, A.; Holmes. 1. B.; Cbao.
`Y.-S.; Bolognese, J. A. J. Clin. Invest. 1982, 69, 913.
`(14) The X-ray crystal structure of eoumactin was first reported by
`Brown. A. G.; Smale. T. C.; King, '1'. J.; Hansenkamp. R..:
`Thompson, R. H. J. Chem. Sac., Perkin Trans. I 1978, 1165.
`Note that the relative configuration in Figure 1 of the cited
`reference does not agree with the crystal coordinates; we
`present here the correct relative and absolute stereochemical
`configuration of compectin.
`
`(11)
`
`(13)
`
`0022-2623/85/1828-0347301150/0
`
`-D 1985 American Chemical Society
`
`Sawai Ex 1023
`
`Page 1 of 12
`
`

`
`Stoklter ct al.
`
`slightly modified procedure of Noltes et al.” provided
`4-hydroxy ketone ll in high yield. Acylation of 11 with
`2-bromoacetyl bromide in the presence of pyridine fur-
`nished bromo acetate 12 which was ring closed to 4-
`hydroxy-4-methyl lactone 13 via an intramolecular Re-
`formatsky reaction.“ Substitution of triethylamine for
`pyridine in the acylation step resulted in elimination of
`the 2-bromoacetoxy moiety and isolation of the resultant
`dienone.
`An alternate route to lactone 13 starting from 4-hydroxy
`lretone ll was investigated. This route involved sequential
`acylation, intermolecular Reformatsky reaction with ethyl
`2-bromoacetate, basic hydrolysis, acidification, and lac-
`tonization. This route was abandoned in favor of the more
`efficient two-step route (vide supra). Ethylene lactone 13s
`was reduced in the same manner as 6a(i) to provide the
`corresponding ethyl-bridged compound 16. Refluxing a
`solution of 13a and toluene in the presence of PTSA (trace)
`resulted in the smooth conversion of 13a to 17.
`5-Methoxy-3-hydroxyheptsnoic acid 20 was prepared by
`treating the dimethyl acetal of 2 with diketene (1 equiv)
`in the presence of TiCl4 by using the general procedure
`of Izawa and Mukaiyama" followed by borohydride re—
`duction, basic hydrolysis. and acidification of the resultant
`3-keto ester 19 as shown in Scheme III. A similar con-
`densation of aldehyde 2 provided a mixture of 3-kete ester
`3 and dihydro lactone A and, thus, was a less expeditious
`route to target lactone 6 than was the dianion procedure
`(Scheme I).
`The previously undescribed requisite aldehydes were
`prepared as shown in Schemes [V-VIII. The synthesis
`of the oz..8-unsaturated aldehyde 55a needed for elaborating
`lactone 55 is shown in Scheme IV with phenanthrene-4-
`carboxaldehyde as starting material This procedure was
`also used to prepare the lmown a,B-unsaturated aldehyde
`precursors for lactones 56-58.
`The 3-(decahydronaphthyl)propanals 25 and 27 (pre-
`cursors to 51 and 52) were elaborated from 21 as shown
`in Scheme V. After high-pressure hydrogenation of 22, the
`acid 23 was converted to aldehyde 25 by the Burgstahler
`modification of the Rosenmund reduction.” The ethyl
`ester of 23 (24, isolated in about an equal amount during
`the workup of 23) was isomerized with AICI3 (2 equiv) at
`room temperature and subsequently hydrolyzed to acid
`26, which was converted to aldehyde 27 in the same
`manner used for 23 -> 25.
`The Dibal reduction of nitriles 29, 32, and 34 (Scheme
`VI) provided the aldehydes requisite for preparing lactones
`47, 48, and 53, respectively. Aldehyde 37 (precursor to
`44)" was prepared by alkylation of phenol 36 with the
`diethyl acetal of 2-brornoacetaldehyde followed by hy-
`drolysis (Scheme VII).
`Finally, conversion of cinnamaldehyde 2 to propargyl-
`aldehyde 41 (precursor to 42) was effected via the four step
`sequence 2 -v 38 - 39 - 40 —~ 41 by using the general
`method of Allen and Edens” as shown in Scheme VIII.
`
`
`(17) Noltes.J. G.; Verbeelr, F.; Creemers, H. M. J. C. Organometal.
`Chem. Synlh. 1970-1971. I, 57.
`In the present case, (ti-i»
`butylstannyl)acetone was prepared in situ.
`(18) For a general method, see: Maruoka, K.; Hashimoto. S.; Kl-
`tagawa, Y.: Yamsrnoto. l-1.: Nozalri. H. J. Am. Chem. Soc. l977.
`99, 7705.
`(19) Iuwa, T.; Mukaiyama, T. Chem. Lett. I975, 161.
`(20) Burgstahler. A. W.; WeigeL L. 0.; Shaefer, C. G. Synthesis
`1976, 767.
`(21) During the course of this investigation. the 4R.6R dechloro
`analogue was prepared from tri-0-acetyl-D-glucal as a possible
`HMG-CoA reductase inhibitor by Yang et al.: Yang. Y. L;
`Falclr, J. R. Tetrahedron belt. 1982, 23, 4305.
`
`348 Journal of Medicinal Chemistry, 1986, Vol. 28, No. 3
`
`SAR,s for oompactin-like mimics and afforded a series of
`moderately effective HMG-CoA reductase inhibitors typ-
`ified by the ring-opened form of lactone 8a(+).
`
`
`
`compncjin R- H
`movmolm. 5- CH3
`
`I
`
`011(9)
`
`Chemistry. The compounds prepared for this study
`are listed in Tables I—III.
`Their syntheses from the
`corresponding aldehydes, exemplified by 2, are shown in
`Schemes I-II]. Condensation of aldehyde 2 with the
`dianion of ethyl acetoacetate" followed by borohydride
`reduction, basic hydrolysis, acidification, and azeotropic
`removal of water provided a mixture of the trans (6a(:h))
`and cis (6b(:h)) lactones which subsequently was separated
`by chromatography (Scheme 1). The use of MeOH in the
`borohydride reduction step was found to be advantageous;
`replacement of MeOH by Et0l-I produced some of the
`corresponding ethyl ester which was more resistant to
`hydrolysis. The resolution of 6a(:£) was accomplished via
`formation and chromatographic separation of the diaste-
`reomeric (R)-oz-methylbenzylamines followed by basic
`hydrolysis and relactonization to yield 6a(+) and 6a(—).
`Hydrolysis and acidification of 5-hydroxy-3-keto ester
`3 without prior reduction resulted in spontaneous lacton-
`ization to enol lactone 4. Numerous attempts to reduce
`4 to hydrory lactone 6, either catslytically or via metal
`hydrides, were unsuccessful. Treatment of lactone 6a(:i:)
`with NH3 provided the erythro amide 10. Catalytic re-
`duction of lactone 6a(¢) provided compound 7 containing
`a saturated bridging unit. The lactol others 8 and 9 were
`prepared by diisobutylaluminum hydride (Dibal) reduction
`of 6a(:l:) followed by treatment with Me0H in the pres-
`ence of pyridinium p-toluenesulfonate (PPTS).
`The syntheses of methyl lactones l3, l6, and 17 are
`illustrated in Scheme II. A tin-mediated aldol condensa-
`tion of aldehyde 2 with 2-acetoxypropene following a
`
`(15) During the course of this study, a series of rnevalonolactone
`derivatives of the general structure were reported to inhibit
`on
`
`cu.‘-We
`
`icn,;
`
`X
`
`I
`
`/\
`
`I-IMG-CoA reductase by Sato er. al; Sato, A.; Ogiso, A.; No-
`guchi, l-l.: Mitsui, 5.; Kaneko, L, Shimada, Y. Chem. Pharm.
`Bull. 1980, 28, 1509.
`(16) Huclrin. S. N.; Weiler, L. Tetrahedron Lett. 1971, 4835.
`
`Sawai Ex 1023
`
`Page 2 of 12
`
`

`
`I-lMG~CoA Reductase Inhibitors
`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 3 349
`
`Table I. Effects of Lactone Modification and Stereochemistry
`
`\ R
`
`
`
`yield.
`70
`52
`
`ml). °C
`168-169
`
`f°1’m“13°
`C,,H,,c1,o,
`
`°°n°“v
`I-‘F/mll
`2
`X0
`50
`
`i"h‘b°
`0
`12
`15
`
`no.
`4:1
`
`og(§)v
`
`cut)
`
`R
`
`Cl
`
`recryst
`solvent
`
`°"
`\
`o
`
`0
`
`vs‘
`
`0
`
`on
`d
`g”
`(1
`o
`““
`o
`
`Eton
`
`acetone/hexane
`
`acetone/hexane
`
`6g(+)
`
`"
`
`n-BuCl
`
`“
`
`0
`
`q
`
`8g(-)
`
`3‘
`
`9‘
`
`n-BuCl
`
`"
`
`g
`
`chronmt. acetone/CH;Cl;
`
`chromat. acetone]Cl-MCI;
`
`°"‘
`El
`o
`0"
`“K0 »,,,°c
`n
`(ll
`0
`cm
`10' wk acetone/hexane
`
`33
`
`17
`
`25
`
`M
`
`33
`
`64
`
`63
`
`148-150
`
`C,,H,,Cl,0,
`
`115-117
`
`C1aHuC120s
`
`114-116
`
`C,3HuCl,03
`
`11¢-116
`
`C;3C1gClg0;
`
`wax
`
`C,4H,.Cl,0,-i/.H,0
`
`88-93
`
`C..H,.Cl,O3
`
`117-118
`
`C,,H,,Cl,N05
`
`1o
`10
`2
`1o
`20
`50
`
`;
`5
`10
`20
`
`;
`4
`3
`3
`5
`2
`8
`10
`1
`3
`8
`
`Q
`4
`10
`4
`2
`1o
`25
`
`84
`
`64
`g
`27
`17
`18
`
`2g
`66
`72
`86
`
`3
`o
`0
`2
`4
`3
`6
`o
`0
`3
`0
`
`2?
`
`3
`5
`15
`
`13a
`
`lab
`
`’'° 35“:
`=
`‘‘"‘°
`0
`
`C“
`\_
`‘
`
`__~°"
`o
`
`n-BuCl
`
`35’
`
`136-138
`
`C,.H,.Cl,O,
`
`n-BuCl/hexane
`
`5.4
`
`185-137
`
`C,.H,.Cl,0,
`
`o
`
`I7
`
`chromat. CHCI,/Me0H
`
`90
`
`108-110
`
`C..HnCl,0,
`
`4
`3
`2
`‘"3
`3
`10
`A
`5
`25
`o
`0
`2
`0
`1
`Cul-l1,Cl,0.‘
`gum
`42"
`chromat. Cl-l,C1,/HOAc
`/{*5/°{/fl\
`20'
`°"
`o
`5
`
`10 0
`‘Analytical results are within $0.49!: of the theoretical values unless otherwise noted. °See Experimental Section for protocol.
`‘ Tested
`in the form indicated since csrboxylate anion could not be formed under this testing protocol. ‘pK, - 5.22 (30% Etol-I). ‘When tested in
`the lactone form only 25% inhibition was observed at 50 pg/mL. ’ Yield from 12 ‘About a 4:3 ratio of erythro and threo.
`‘Overall yield
`from 18. ‘Anal. Calcd: C, 62.68. Found: C, 52.02.
`
`The synthesis of 43 (the Z isomer of 6a(-.t)) was accom-
`plished by the catalytic hydrogenation (Lindlar) of 42.
`Biological Results and Discussion
`The compounds listed in Tables I-IV were evaluated for
`their ability to inhibit solubilized, partially purified rat
`liver HMG-CoA reductase. During the initial phase of this
`study, both the lactone and the ring-opened sodium di-
`
`
`(22) Allen, C. F. !-1.: Edens, C. 0., Jr. ‘Organic Syntheses”; Wiley,
`New York, 1955; Collect. Vol. III.
`
`hydroxycarboxylate forms of each compound were tested
`for intrinsic inhibitory activity. In each instance, the so-
`dium dihydroxycarboxylate form proved more active than
`the lactone form (see Table I, footnote e). Accordingly,
`subsequent tests were done exclusively on the sodium
`dihydroxycarboxylate forms unless noted otherwise.
`The contributions of lactone moiety stereochemistry and
`functionality to intrinsic inhibitory activity in compound
`6 are illustrated in Table I. Separation of the lac1one
`mixture 6 into the racemic cis (6b(é)) and trans (6a(*))
`isomers showed that activity resided principally in the
`
`Sawai Ex 1023
`
`Page 3 of 12
`
`

`
`350 Journal of Medicinal Chemistry, 1985, Vol. 28, No. 3
`
`Stem," at “L
`
`Table 11. Effects of Bridge Modification
`
`
`
`"°~
`
`A
`
`recrynt
`-olvm
`
`yield,
`%
`
`mp. °C
`
`formula‘
`
`concm
`pg/ml.
`
`«jg,
`inhib‘
`
`1
`2
`5
`10
`
`1
`2
`4
`
`8
`0.625
`3.125
`
`0.625
`3.125
`
`1
`2
`4
`10
`5
`10
`20
`50
`
`5
`10
`20
`50
`5
`10
`20
`50
`
`25
`10
`25
`
`29
`38
`57
`H)
`
`14
`26
`37
`
`88
`0
`8
`
`0
`0
`
`21
`24
`18
`21
`4
`26
`27
`23
`
`16
`9
`7
`18
`19
`29
`45
`61
`
`7
`25
`35
`
`.. 5A\\“ A0
`
`cu
`
`7
`
`/C"zC"z/
`
`"'B“Cl
`
`60
`
`93'”
`
`Cl8Hl4Cl2o3
`
`18‘
`
`,cu,cu,/
`
`chromat. CH,Cl,/acetone
`
`50
`
`87-88
`
`CuH,,Cl,O,
`
`—C=C—
`
`chromat. Cflgclg/BCGIODG
`
`_
`viscous oil
`
`C13}-l,oCl,O3
`
`"\c=c/it
`/
`\
`
`,ocu,/
`
`chrornat.‘ IPA/hexane
`
`96-98
`
`chromat. CH,Cl,/acetone
`
`4.2‘
`
`oil
`
`C1,H,,Cl,O3
`
`C,,H,,C|,0.
`
`J
`
`ll
`
`50
`
`rt-BuCl
`
`13‘
`
`133-135
`
`CuHmClg03
`
`\/
`
`CH,Cl,/n-Cgl-l,Cl
`
`24‘
`
`104-107
`
`C151-["03
`
`42
`
`43
`
`44
`
`45
`
`46
`
`47
`
`/¢;..,c...:/
`
`chromat. CH,Clg/acetone
`
`9.5‘
`
`gum
`
`C,-,1-1,30,-'/,1-1,0
`
`‘B
`
`/C" ,5“, c”,/
`
`CIIIOIIIII. Cflgclg/30e$0n3
`
`I6‘
`
`Oll
`
`Clgiiwoyl/mC3l"lgo
`
`‘See Experimental Section for protocol.
`‘Analytical results are within £0.47. of the theoretical values unless otherwise noted.
`‘Equatorial 4-Me in lactone by reduction of 131.
`‘Overall yield from aldehyde.
`'HPLC purification on Dupont silica 10/30 with i-
`Pr0H—hexsne (1:19, v/v) at 2 mL/min. Times of elution are 13.2 min for 42 and 21.8 min for 43.
`
`racernic trans lactone (6a(:h)). Resolution of 6a(:t) af-
`forded enantiomers 6a(+) and 6a(—); their evaluation
`showed that the activity displayed by the racemate re-
`sulted solely from the dextrorotatory isomer. The addition
`of a methyl group to the 4-position of 6a(:i:) to give trans
`lactone 13a, a compound which more closely resembles the
`I-IMG moiety of the substrate HMG-CoA, did not alter
`activity appreciably. However, cis lactone 13b, which
`possesses the opposite relative stereocbemistry at C-4, was
`much less active as anticipated from the results obtained
`for 6a,(i) and 6b(i).
`Interestingly, oxidation of the 4-
`hydroxyl group of 6a(:t) to provide enol 4 greatly reduced
`activity. This result is a likely consequence of the fact that
`4 readily forms the sodium salt of the enolate and,
`therefore, fails to undergo ring opening to afford the re-
`quired carboxylate anion under alkaline conditions. Re-
`placement of the enolic hydroxyl group in 4 with a methyl
`group to provide 17 further reduced activity. Replacement
`of the carboxyl group in the ring-opened form of 6a(:k)
`with a carboxamido group ([0) ablated activity as did
`conversion of the 5-hydroxl group to the corresponding
`
`methyl ether (20). These results demonstrate the im-
`portant contributions of the carboxylate and 5-hydroxyl
`groups to activity. Finally, it should be noted that lactol
`ethers 8 and 9 displayed greatly diminished activities.
`The effects of altering the moiety bridging the aromatic
`and the lactone fragments in 6a(t) on intrinsic inhibitory
`activity are shown in Table II. Saturation of the ethenyl
`bridge in 6a(£) and its 4-methyl derivative 13a(i) gave
`ethyl-bridged compounds 7 and 16. respectively, with little
`change in activity. However, other modifications of the
`bridge such as replacement with the ethynyl (42), cis-
`ethenyl (43), and oxymethylene (44) groups resulted in loss
`of activity as did complete removal (45) of the bridging
`moiety. In a companion series of naphthalene analogues
`(Table II), compound 47 containing the saturated two-
`carbon bridge proved superior. Increasing the length of
`the bridge to three carbons (48) reduced activity and
`elimination of the bridge to provide 46 further reduced
`activity.
`The results of various carbocyclic moieties substituted
`at the 6-position of the lactone ring are shown in Table
`
`Sawai Ex 1023
`
`Page 4 of 12
`
`

`
`HMG-CoA Reductase Inhibitors
`
`Table III. Effects of 6-Substitution
`
`01-1
`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 3 351
`
`x\“‘
`0
`
`t
`I Id.‘
`concn.
`%
`:(e)l:\xI:’!'ll.
`y git
`ug/mL
`inhib‘
`Et,O/pet. other
`~8-l0
`13
`(1)
`20
`0
`50
`36
`
`X
`
`0/
`
`mp. ‘C
`56-58
`
`formula“
`Cul-{"03
`
`no.
`49
`
`max
`
`51-:
`
`52-4'
`
`saw‘
`
`54
`
`55
`
`k
`
`56
`
`©/can
`© C“=c“/
`O O
`/'
`@‘
`@
`
`I
`57 @
`O
`
`58"
`
`©
`'_
`
`.0
`
`n
`
`n-BuCl
`
`.
`IIBUCI
`
`.3 c1
`11
`
`n
`
`n-BuCl
`
`,.,c,,‘/
`
`UC
`
`H gu,c»./
`CD
`‘.1
`G3
`74
`
`v~‘°"‘°“'
`
`Et,0/hexane
`
`~3-10
`
`69-70.5
`
`c.,H,,o,I
`
`121,0/hexane
`
`~3-10
`
`as-71
`
`c,,H,0,0.1H,0“
`
`,
`
`Et,0/hexane
`
`~23-10
`
`102-110
`
`c.,1-1,03
`
`Et,0/hexane
`
`~s-1o
`
`122-129
`
`c,,1-1.0,
`
`/
`
`Et,O
`
`23
`
`25
`
`3
`
`12
`
`10
`
`96-98
`
`C,,..H..0,
`
`140-142
`
`151-152
`
`gum
`
`C,,l-L503
`
`C H 0
`10
`1s
`
`3
`
`c 1-1 0
`2,
`,3
`
`3
`
`143-144
`
`c,,H,.o,
`
`13
`2o
`50
`
`13
`20
`50
`1
`5
`12.5
`1
`
`5
`10
`20
`50
`3.3:1.0
`
`0.1
`0-2
`0.4
`0.3
`0.1
`0.2
`0.4
`
`0.2
`0.1
`0.4
`0.3
`
`2:
`17
`34
`
`44
`70
`1
`13
`28
`18
`as
`3
`15
`14
`31
`
`64
`
`25
`46
`61
`81
`20
`34
`42
`
`as
`22
`14
`20
`
`“Overall yield from aldehyde. “Analytical results are within $0.47: of the theoretical values unless otherwise noted. ‘See Experimental
`Section for protocol. ‘ Mixture of trans/cis; 1.4/ 1.
`'Percs11t inhibition calculated as if contribution of cls isomer was zero. ’Ansl. Calcd: C.
`68.99. Found: C. 68.54. ‘Mixture of tram/cis; 28/1. "Anal. Calcdz C. 72.82. Found: C. 72.27. ‘Mixture of trans/cis: 3.8/ l. 5 Mixture of
`trans/cis; 2/ 1. ‘Preparation of aldehyde. mp 112-116 °C; Hennion, G. F.; Fleck, B. R. J. Am. Chem. Soc. 1955, 77, 3253. ‘Preparation of
`aldehyde, mp 96-98 °C; Bergmann, E. D.; Weiler-Feilchenfeld, H.; Mandel. N. Viecnamica Chim. Acta 1966, 129; Chem. Abstr. 1972, 72,
`3276s. "Preparation of aldehyde. mp 42-44 ‘C: Kohler. E. P.; Larsen. R. G. J. Am. Chem. Soc. 1985. 57. 1452.
`
`III. The decahydronaphthalenes 51 and 52 and tl1e ada-
`mantyl compound 53 all possessed similar activity, while
`the cyclohexanes 49 and 50 were less active. Aromatization
`of the cyclohexane ring to give the phenyl derivative 54
`had little effect on activity. However, substitution of the
`bridging moiety with larger aromatic groups such as those
`in compounds 55-57 increased activity about 10-fold, i.e.,
`to about 1% of the inhibitory activity of compactin.
`Scission of the 4a-4b bond of compound 56 provided a less
`compact molecule 58 with diminished activity.
`The [C3, and relative potency values of the most active
`compounds evaluated in this study are compared in Table
`IV. Although the compounds described above are only
`moderately active HMG-CoA reductase inhibitors. analysis
`of their intrinsic inhibitory activities suggests that inhibitor
`
`binding to HMG-COA reductase is sensitive (a) to the
`stereochemistry of the lactone moiety, (b) to the ability
`of the lactone moiety to be opened to s dihydroxy acid,
`(c) to the length of the moiety bridging the lactone and
`the lipophilic groups, and (d) to the size and shape of the
`lipophilic group. Further modifications of the lipophilic
`group leading to more potent inhibitors 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 CDCI3, unless noted otherwise, on either
`a Varian T-60, EM-390, or NT-360 spectrometer. Chemical shifts
`are reported in parts per million relative to Me.S1' as the internal
`standard. Elemental analysis for carbon, hydrogen, and nitrogen
`
`Sawai Ex 1023
`
`Page 5 of 12
`
`

`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 3
`352
`Scheme 1
`
`Stokker et al.
`
`OH
`
`\
`
`\
`
`0
`
`0
`
`cu
`
`Cl
`
`c. D
`
`4
`
`O
`
`0
`
`CI
`
`OH
`
`OH
`
`0
`
`ocrig \ //' mHs
`
`co
`
`5
`
`cu
`
`\ an
`
`2 1
`
`., a
`OH
`
`CI
`
`Cl
`
`CI
`
`\
`
`7
`
`<31
`
`Cl
`
`OH
`
`61
`
`—'—
`
`CI
`
`4', 0,0
`
`OH
`
`H
`
`
`Illlc
`Cl d l
`+ (1
`
`30(2)
`
`BN3)
`
`OH
`
`0H
`
`63
`31;?‘
`0 "got":
`
`+ 6‘
`722:“ 0
`ocna CI
`
`9
`
`1.
`OH
`
`
`OH
`O
`
`/. 6'. D. 0
`
` NHz
`sou) + sat-)
`
`I0
`
`’’H'. ‘OH.
`-"éH,coEH,co,ci-1,.
`i (R)-(+ )-c,H,cH(cH,)NH,_
`
`‘*NaBH,,E:oH.°c,H,cH,,A.
`
`'1-r,,Rh/c.
`
`'Dibal. "cH,oH,rrTs.‘Ni-1,.
`
`Table IV. In Vitro Inhibitory Potencies against HMG-CoA
`Reductsse
`
`no.
`compactin
`6a(:2]
`6a(+)
`7
`13:
`16
`47
`51
`51
`55
`55
`57
`
`[C5o,"b
`uM
`0.01
`22
`10.8
`15.2
`20
`19.8
`129
`1M
`90
`1.9
`0.89
`1.6
`
`[Bl
`potency“
`100
`0.08
`0.18
`
`0.09
`0.08
`
`1.1
`1.5
`0.9
`
`°1C.,, is the rnicromolar concen-
`‘Relative precision is *10%.
`tration of the inhibitor required to give 50% inhibition under the
`conditions of the assay system.
`
`were determined with a Perkin-Elmer Model 240 elemental an-
`alyzer and are within :!:0.4% of theory unless noted otherwise.
`Optical rotations were determined with a Perkin-Emer Model
`141 polarirneter. All starting materials were commercially available
`unless indicated otherwise.
`3-(2,4-Dlohlorophenyl)-2-propane] (2) was prepared by
`modification of the procedure of Baker.” A solution of Nam!
`
`(23) Baker. B. R.; Janson. E. E.: Vermeulen. N. M. J. J. Med.
`Chem. 1969, I2, 898.
`
`(0.125 g) in CH,OH (2 mL) was added dropwise to a stirred
`suspension of 2.4-dichlorobenzaldehyde (7.5 g, 0.043 mol) in ac-
`etaldehyde (30 mL) cooled in an ice bath. The resulting solution
`was stirred 30 min with cooling, diluted with acetic anhydride
`(25 mL), and heated at 120 ‘C for 1 h. This mixture was cooled,
`diluted with H20 (60 ml.) and 6 N I-lCl (25 mL), and heated at
`100 °C for 0.5 h. The light brown, oily product solidified upon
`cooling. It was collected, dried, and triturated with Et4O to provide
`2 (8.5 5, 98%), mp 106-108 °C. An analytical sample was prepared
`by recrystallization from hexane to provide 2 as a pale yellow solid:
`mp 107-108 °C; NMR 6 6.70 (H, dd, J = 15, 6 Hz), 7.20-7.73 (3
`H, m). 7.87 (H. d, J - 15 Hz), 9.8 (H, d, J - 6 Hz). Anal.
`(C91-I.Cl,O) C, H.
`Methyl (E)-7-(2,4-dichlorophenyl)-5-hydroxy-3-oxo-6-
`heptenoate (8) was prepared by a modification of the procedure
`of Weiler.“ Methyl aoetoaoetate (23.2 g, 0.2 mol) was added
`dropwise to a stirred suspension of sodium hydride (50% oil
`suspension) (10.5 g, 0.22 mol) in anhydrous THF (500 mL) at 0
`°C under a N2 atmosphere. The resulting solution was stirred
`15 min at 0 °C and then treated with a 2.2 M solution (95.4 mL,
`0.21 mol) of n-butyllithiurn in hexane over 10 min. The yellow
`solution was stirred 15 min at 0 ‘C and then was treated with
`a solution of 2 (44.2 g, 0.22 mol) in anhydrous T111‘ (250 mL).
`The resulting orange solution was stirred 15 min at 0 “C and then
`quenched by dropwise addition of 12 N HCl (48 mL). The reaction
`mixture was diluted with 1-120 (300 mL) and extracted with Et,O
`(3 X 300 mL). The organic extracts were combined, washed with
`brine (2 X 200 mL). dried over MgSO.. and filtered. The filtrate
`was evaporated in vacuo. leaving a red oil. The red oil was stirred
`in petroleum ether (200 mL) in order to remove the mineral oil.
`The mixture was cooled and the petroleum ether decanted to
`provide 62.8 g (90%) of 3: NMR 6 2.83 (2 H, d, J I 6 Hz). 3.47
`
`Sawai Ex 1023
`
`Page 6 of 12
`
`

`
`HMG-CoA Reductase Inhibitors
`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 3 353
`
`Schema ll
`
`,_ 5
`2 H3.-
`
`Cl
`
`CI
`
`OH
`
`O
`
`CH3
`
`\
`
`11
`
`/ \
`
`0
`CI
`DJl\°/B’
`C]
` fi \
`
`Q
`
`Cl
`
`12
`
`14
`
`'
`
`Cl
`
`\
`
`15
`
`/40,1"
`
`Schema Ill
`
`Cl
`
`OCH;
`
`2
`
`.
`
`cn
`
` ocH3 + U _"_‘.
`
`0
`
`I3
`
`Cl
`
`OCH! 0
`
`0
`
`\
`
`OCH;
`
`."_"'.
`
`0/
`
`0
`
`CH3
`
`Cl
`
`OE?
`
`CH3
`
`r;{MeOH_PTSA.
`Scherne IV
`
`19
`
`Cl
`
`cu
`
`och, on
`
`0
`
`\
`
`OH
`
`20
`
`1* TiC|,. °Me0H.
`
`4 NaBH.-
`
`‘OH’-
`
`H0
`
`$CH3
`
`61
`o 4- cm isomcr
`13b
`
`\\\“ O
`
`C’
`
`Cl
`
`13¢
`
`/ \
`CH3
`8‘
`
`H0
`
`CH3
`
`17
`
`CI
`
`b no,cco,H.
`- (n-au),snocn,,cn,=c(oAc)cn .
`BrCH,COBr,C,H,N.
`«1 zn.cuBr.éz,A1c1.
`° Ac,O,
`.
`fBrcH,co,E:. ‘on: ’'H‘. *A,c,H,cH,.
`,, nmc.
`* PTSA, c,H,cH,, A.
`(2 H, s),
`.70 (3 H, 8), 4.76 (H.111), 6.13 (H, dd. J - 15, 6 Hz), 6.90
`(H. cl. J - 15 Hz). 7.0-7.5 (3 H. In).
`(E)-6-[2-(2.4-Dichlorophonyl)athenyl]-5,6-dihydro-L
`hydroxy-2H-pyran~2-one (4). The ester 3 (2.0 3, 6.3 mmol) was
`stirred in 0.1 N NaOH (200 mL) for 4 h. The resulting solution
`was acidified with 6 N HCl to provide a yellow solid which was
`recrystallized to analytical purity: yield 0.93 3; NMR (M°gS0’d3)
`6 2.60 (2 H, m), 5.00 (H, s), 5.13 (H, m), 4.67 (H, dd, J II 15, 6
`Hz), 6.97 (H. d. J = 15 Hz), 7.27-7.87 (3 H, m), 11.5 (H, br s).
`Methyl
`(E)-7-(2,-4-Diohlorophanyl)-3,5-dlhydl'oxy-8-
`hepteaoato (5). Sodium borohydride (1.3 g, 33.7 mmol) was
`added with stirring to a cooled solution (5 'C) of 3 (10.7 g, 33.7
`mmol) in Et0H (100 mL) at a rate sufficient to maintain the
`internal umperature at 15-20 ‘C. The resulting solution was
`stirred an additional 2 h with ice-bath oooling and then acidified
`with 6 N HCI. The resulting mixture was diluted with H10 (250
`ml.) and extracted with Et.,0 (3 X 200 mL). The Etg0 extracts
`were combined. washed with brine, dried over MgSO., and filtered.
`The filtrate was evaporated in vacuo to provide a yellow oil (10.4
`g, 97%). A portion of the oil was purified by medium-pressure
`chromatography on a 25 X 1000 mm silical gel column. Elution
`
`..."“
`
`° LiCH=CHOC,H,.
`
`5 Silica gel.
`
`Scheme V
`
`HO
`
`21
`
`C02H
`
`/
`
`’
`
`* @ A
`
`22
`
`H §\,C0zE'
`
`H” §.\,oozn
`
`H” \.\,cuo
`
`+
`
`5:!
`
`H
`
`24
`
`::Im
`
`28
`
`Sun
`
`27
`
`1* I-1,,Ru/C, moi-I.
`H cH,(co,H),,c,H,N.
`d H,,Pd.’C,2,6-(Me),C,H,N.
`9 AlCl,.
`foH-.
`
`C soc1,.
`-1 H‘.
`
`with CH9Cl,-CHa0H (49:1. v/v: 500 mL) Drovided a forerun which
`was discarded. Continued elution with the same eluant (3500 mL)
`provided 5 as a yellow oil; NMR 6 1.60-1.93 (2 H, m), 2.50 (2 H,
`d,J I 6 Hz), 3.67 (3 H, 3), 4.13-4.77 (2 H, m), 5.93-6.40 (H,m),
`6.93 (H, d, J I 15 Hz), 7.17—7.50 (3 H, in). Anal. (C1,!-l,.Cl,0‘)
`H: C: calcd, 52.68; found, 52.25.
`(E)-6-[2-(2,4-Dichlorophonyl)ethenyl]-3,4,5,6-totrahydro-
`4-hydroxy-2H-pyran-2-one (6a(t) and 6b(t)). An E101-I so-
`lution (100 mL) containing 5 (8.4 g, 26.3 mmol) and 1 N NaOH
`
`Sawai Ex 1023
`
`Page 7 of 12
`
`

`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 3
`364
`Scheme V]
`
`=' * @@
`
`©@
`
`o -@<<§ oo
`
`32
`
`33
`
`_L_
`
`CN
`
`CHO
`
`34
`
`3
`
`0 NCC1-I,C0,i-i, Nn,oAc. C,H,N.
`4 NaCN.
`Scheme VII
`
`° H,, Pd/C.
`
`c Dibai.
`
`CI
`
`Cl
`
`OH
`
`/ LL
`
`CI
`
`Cl
`
`35
`
`° BrCH,CH(0Et),.
`Schema VIII
`
`cu
`
`'’ 2N H,so..
`
`CHO
`
`37
`
`cu
`
`‘ ‘
`2 4.
`
`cl
`
`°'
`
`cu
`
`\ cno
`3!
`
`E
`a
`
`38
`
`CH(0E1)g
`
`3'
`
`\
`
`39
`
`cu
`
`1.
`
`cu
`
`c=c—cH<oen), 1-
`
`40
`
`"
`
`Cl CECCHO 7-"-'5
`
`41
`
`U
`
`C\‘\\ 0
`
`c/¢
`
`O —"
`
`Cl
`
`42
`
`or
`
`Cl
`
`on
`
`fl
`
`0
`
`0
`
`\\“\
`43
`
`° (Eto),CH,NH,,ci. d KOH.
`" K,Co,.
`4 Br,
`9 Dilute H,so,,.
`’ 5-7. Pd/CsCO,.
`(26.8 mL) was stirred at ambient temperature for 1 h. The
`reaction solution was acidified with 8 N HCl. diluted with H20
`(200 mL), and extracted with Ego (3 x 100 mL). The combined
`
`Stokker et al.
`
`organic extracts were washed with brine, dried over MgSO., and
`filtered The filtrate was evaporated in vacuo to provide a mixture
`of acid and lactone (7.8 g, 97%). A solution of this mixture in
`toluene (100 mL) was heated at reflux in a Dean—Stark apparatus.
`After 2 h, the Dean—Stark apparatus was replaced with a Soxhlet
`containing 3-A molecular sieves (100 g). The solution was refluxed
`for an additioml 4 h and than the toluene was removed in vacuo
`leaving a yellow oil (7.2 g, 95%) which was a mixture of 6s(-.l:]
`and 6h(#). The oil was ehroamtographed on a silica gel column
`(500 g). Elution with CH,Cl2-acetone (4:l, v/v; 9(1) mL) provided
`a forerim which was discarded. Continued elution with the same
`eluant (300 mL) gave the trans isomer 6a(:) (2.5 g). Recrys-
`tallization of the solid provided an analytical sample. as colorless
`needles: NMR (acetone-dg) 6 2.06 (2 H, m), 2.69 (2 H, m), 4.43
`(H, m), 5.42 (H, In), 6.49 (H, dd, J = 15, 6 Hz), 7.08 (H, d, J -
`15 Hz). 7.33-7.59 (2 H. m), 7.79 (H. d, J = 8 Hz). An isomeric
`purity of 99.8% was determined for 6a(:£) by HPLC on a
`Whatman Partisil-5 RAC column with 15% 2-propanol/hexane
`as the eluant. The time of elution was 4.96 min at a flow rate
`of 6 mL/min.
`Further elution of the column with the same eluant (600 mL)
`gave the cis isomer 6h(i) as a solid (1.25 g). Recrystallization
`gave an analytical sample as colorless needles: NMR (acetone-d.)
`6 1.50-2.93 (4 H, m), 4.35 (H, m), 5.02 (H, m), 6.37 (H, dd, J 3
`15, 6 Hz), 7.02 (H, d, J 8 15 Hz), 7.16-7.50 (2 H, In), 7.67 (H, d,
`J = 8 Hz). An isomeric purity of 99.3% was determined for 6h(:h)
`by HPLC on a Whatnian Partisil-5 RAC column with 15% 2-
`propanol/hexane as the elunrit. The time of elution was 5.79 min
`at a flow rate of 6 mL/min.
`trans-6-[2-(2,4-Dlchlorophenyl)ethyl]-3,4,5,6-tetrahydro-
`I-hydroxy-2H-pyran—2—one (7). A solution of 6a(*) (1.5 g, 6.2
`mmol) in THF (100 mL) was stirred magnetically and hydro-
`genated at room temperature under atmospheric pressure in the
`presence of 5% rhodium on carbon (150 mg) until 1.25 molar equiv
`of hydrogen had been consumed. After removal of the catalyst
`by filtration, the filtrate was evaporated in vacuo, leaving a solid.
`The solid was recrystallized to provide 7 (0.9 g): NMR 6 1.67-2.17
`(4 H, in). 2.60-3.13 (4 H, m), 4.30-4.50 (H. m). 4.57-4.90 (H, In),
`7.14-7.44 (3 H. In).
`Resolution of (t)-trans -(E)-0-(2-(2.4-Dlchlorophenyl)-
`ethenyl]-3,d.5.6-tetrahydro—4-hydroxy-2H-pyran-2-one (6a).
`A solution of 6a(£) (2.87 g, 10 mmol) in (R)-(+)-a-methyl-
`benzylamlne (15 mL) was stirred for 16 h at ambient temperature
`and then poured into H20 (100 mL). This aqueous mixture was
`acidified with 6 N HCI and extracted with Et40 (3 X 100 mL).
`The Etao extracts were combined, washed with brine, dried over
`MgSO., and filtered. Evaporation of the filtrate in vacuo provided
`the crude diastereomeric amides as a tan viscous oil (4.1 g, 100%).
`This oil (3.1 g. 7.6 mmol) was chromatographed on a silica gel
`column (200 g). Elution with acetone-CH,Cl, (124, v/v; 1200 mL)
`gave a forerun which was discarded. Continued elution with the
`same eluant provided the mixture of diastereomeric amides as
`a viscous oil (3.0 g, 97%). This mixture was separated by chro-
`matography on a Waters Prep LC 500. The separation was
`accomplished by using two Prep PAK-500 silica cartridges in series
`and eluting with acetone-CH,Clg (1:4, v/v). Use of the shave-
`recycle technique provided diastereomer A (1.36 g) and diaste-
`reomer B (1.2 g).
`Recrystallization of diastereozner A from n-butyl chloride gave
`colorless clusters (10 g) which