Transformations of Eburicoic Acid. \ . I Cleaiage of Ring Lt1)) the Fungus Glornerella .fusarioi&s
111further pursuit of our studies of coiivertiiig the diiiiethyl ester (IIb). 111 the rxpectatioii that tlie vwy abundantly available fungal metabolite eburicoic acid difficultly hydrolyzable 21-carbomethoxy group ~ v o u l d (I) into biologically active steroids we were intrigued by resist saponification the diester was treated with 1 AT thc close siiiiilarity in structure between this tetracyclic IiOH i l l niethaiiol a t rooiii tempcraturc to afford iii tritcrpenoid acid and the steroid antibiotics cephaloescclleiit yiclld iiioiioiiiethJ.1 ester acid IIc, characterized bpoiiii Iielvolic acid3 and fusidic acid.4 *\lthough by titration aiid by ail i i i11.r.sigiial at T 6.38 indicating the stcrc~ocheniistryof these antibacterial agents has a siiiglc Incthoxyl group. .I parallel scrips of cxpclriiiot as yet bcen fully established there is 110 doubt that iiieiits v a s performed n i t h tlic dihydro acid IIIa oblikc ebuiicoic acid and related acids deiived from T+ oodtained by rtaduction of thc 24(28)-double bond in 1T:t ~.ottingfungi, they are tetracyclic triterpenoids p with palladiuiii o i i charcoal. The presence of this iiig a carboxyl group in the 21-position. I t 17 tlorihlc I)olid i i i l l a ah hirther substantiated Iiy the. iiitcrcst i n this couliectioii that tli(>clowly Ivlatc> c*haractcriqtit.t i 111.1'. sigiial at T 5.07 (pyridine) a i d tliv porcwic acids have breii slio\vii t o p o i a r s s aiititmctci IUI ('11 oiit-of-plaiir. cleforiiiatioii band a t I 1 "5 p , both of :tctivity, polyporenic acid .I agaiiist ,Sfaphylococc us \\ hicli arc :tl)s(Jiit in tho tlihydro acid. airreus and polyporenic acid (' against .l/ycobacterziiin rl'lic,i (' rc*iiiaiiicd t o accounted thc. filth oxygrii phlei and A/. smegmatis.' Aliiior chciiiical cliangc.: atoiii, ~ihiclia a s shov i i to 1)cl present as a tcrtiary hyiiiight therefore convert the antibacterially inactive. droxyl group hy wductioii oi seco acid IIa with litliiiiiti (Aburicoic acid into ail activr substancc. T i i the. hop(% :~liiiiiiiiiiiiilipdrid(. to f'oriii triol TIr&, which 011 accltylathat such changes might be brought about by iiiic.robia1 ( H? (wzyiiirs we have investigated thca susceptibility 01 T {OO(' 11 dmricoic acid to transforniation 1)y riiici~oorga~iisi~i~ Among the iriicroorganisins found capalilt. 01 attackiiig this substrate with the production of I I I O I Y J polai, ploducts -\vastlie fungus Glomerella f irsarioidc,\ (.YI'CC' '3,?32) Paper chroriiatograiiis of broth saiiiplcs derived fro111 f milentations using this fungus showed spotb causing a calear zone of inhibition when su1)jcc.tc.d to hioautography oil agar plates inoculated with Staphylococcus auwus 209P. When larger scale fc~iiientatioiisTI ci c' carried out with this organism there wab obtained after filtration of the broth and acidification to pH 1 0 a flocculent precipitate froiii which isohutyl iiietliyl kctotics vstracted a iiew ciystallirie acid. 'l'lii.: acid (111.1) 2:% -238", ["ID +78" (EtOH) \vas s ~ o \ \11 t o I)(' :,!I7
tvlliiv
11, 10.0:;. I'ound iY.ti1, 7Cj.67: lT,
(l,
rlie ubvve wriditions when applied to 40-1. ferruentors yieltletl eburicoic acid (two fermentors: 3i)O y of I/rnl., 122 rriethyl isobut,)-lketone-soluble material, which after trituration witli chlurofurrn afforded 2.22 g. of crystalline 1n:tteri:al. Krc*rystalliz:itionfrom acetone gave. :) total of 1.64 g. of 11~1. Ttw tliinrthyl ester (Ilb) of the &(JW acid (300 ing.) w:is p r ~ pared from avid 110 with ethereal diazoniethme i n riiethnric~l( t i nil.). I t cuultl ncit be crystallized. 3,4-Seco-~S~~'~28J-eburicadien-4-01-3,21-dioic Acid 21-Methyl Ester (11~):- A solution of 300 nig. of the dimethyl ester Of ;;,4s r ( ~ ) - A2~'-eLr~rii~:~dien-4-ol-3,21-dioic ~~*~' acid IITb) iri 30 rnl. of t KUH i n n i r t h l i o l \\-itsallowed to stand at roorii terriper:iture for (j tir. The riiistiirr w:ts :iridified with hydrochloric acid, the rnettra i i o l wxs r ( ~ i ~ i i i v ein d i w u o , and the suspension rxttxctetl wi1.h ~ ~ i ~ l l ~ i J f ~ l The ~ l l l~ . ~ h l u r ~ i f o rextract rii w:is dried over sodium sulE:ttc, liltereci, : i r i t l thr. solvent w:is removed r'rz w m o . Th~b residue 1 : 3 l t i i n n . ) on rec,r!-st:tlliz:lti[Jii frclrii hrxiiie dforclml XJ,-J nig. I J ~piire rrionoriiethyl ester IT(,, r t i . p . 14s 1.50'; [n12'ii 1, CHCI, ) : i z 3 . 0 0 ,'5.76, ~ 5.S4, ~ (i.O!l, ~ :ind 1 I .2:3 p . l(.tl. ('82H;,?O-,: (', 74.:;;: I{, I I I 14. Fi~li~iil: f015
€I, 1U.03. 3,4-Seco-P-eburicen-4-oI-3,2l-dioic Acid (1IIa.i.---'Y~I :I pwretlutwl suspensiori of 25 rng. of 1OC; Pd-o:i-i,ti;irco:ll c n i d y s t , i i i :ilc,thol (upralic 1 .6 nil.) was added 2,5 rng. of :j,-t-seco-"*'[?~' ic,adien-l-c1l-a,2l-dioic: w i d (IIa) in 2 nil. of alcohol. €Letluc*til,ri \WS c~inipleteafter I .4nil. uf hydrogen had been tnkrii . 1.2 i n l . ' ~ T h e solution ws filtered and evaporated t i l iiwi/ii. The crystallirie residue upon recrystal1iz:ttioii froin ilieth:lniJl g:ive pure dihb-dro :id 1113, ni.p. 242-2l:i"; [ ( Y ] ' ~ I +%I" ) ( C 0.4, dcohol); 3.00 atld 5.88 p. :twi/. C:tl(d. for C',I,H,?Oj: C , 73.76: H. 10.3s. Fourid: (', i3..5!j H, 10.lh. 3,4-Seco-Ah-eburicen-4-ol-3.21-dioic Acid 21-Methyl Ester (IIIb).-----Tlie tlikiydro acid 111; (50 mg.) wis suspended i n I 1111. ot' iiic.thanol and methylated with etherenl diazomethane. 'I'lit. aniorphuus dinietli~-lester recovered upon removal of the SiJlVeilis z i i L'UCUO was dissolved i i r 5 ii11. i i f O r ; KOH in methanol anti al-l i J \ V ( ? dto reiiiain :it I'OOIII trniperature for 6 hr. T h r i niixture wis t t i c i i acidified with liydrochloric acid, the metlianol removed iri u ~ c u o , and i h ( ~ siispensiori extracted with chloroform. 'I'hc~ I'~iiIJrtJf0~ill c x t r : i ~ *was ~ dried over sodium sulfatc, filtered, air(l
(.I,
i4,:jY:
: I O J S. C . I'aii. -4. I . L:iskin, : ~ n d1'. Principe, J . Chromatog., 8 , :$2 : l O t i S ~ . !?(I) TI. I.. llciri nnd 11. Leilerw, H i o r h ~ m .J . , SO, 60 (l!lfil).
STRVCTURES RELATED TO MORPHINE.XXT'II
July, 1964
evaporated to dryness in vucuo. The dihydromonomethyl ester (IIIb) was recrystallized from acetone-hexane and furnished 37 mg. of pure product, m.p. 170-172'; [ a I z 3 D +76" ( c 0.34, alcohol); h::: 3.05, 5.78, and 5.85 p ; n.m.r. (CDCla) T 6.36 (OCH3), 8.72 (4,4-dimethyl), 8.84 (19-methyl); neut. equiv. 513. Anal. Calcd. for C,nHuOa: C, 74.09; H, 10.49; OCH1,5.98. Found: C, 73.93; H, 10.49; OCH3, 6.28. The above dihydromonomethyl ester I I I b was also obtained when the monomethyl ester IIc (50 mg.) was hydrogenated in ethanol ( 5 ml.) with 50 mg. of 10% Pd-on-charcoal catalyst. 3,4-Se~o-A~~~~(~8)-eburicadien-3,4,21-trioI (IVa).-A solution of 200 mg. of the 3,4-seco-A~~24(28~-eburicadien-4-ol-3,21-dioic acid ( I I a ) in 20 ml. of freshly distilled tetrahydrofuran was added dropwise over a 15-min. period to a suspension of 200 mg. of lithium aluminum hydride in 30 ml. of tetrahydrofuran. The mixture was refluxed for 3 hr. and, after cooling, 0.5 ml. of a saturated sodium sulfate solution was added. The suspension was filtered, the precipitate washed three times with hot chloroform, and the solution evaporated to dryness in vacuo. The residue (197 mg.) on recrystallization from acetone gave 160 mg. of pure triol IVa, m.p. 148-149"; [aIz3D+89" ( C 0.59, CHC13); '":A:; 3.08, 6.10, and 11.38 p ; n.m.r. (CDCl,) 7 5.26 (28-CH2), 6.33 (m 3- and 21CHZ), 8.67 (4,4-dimethyl), 8.83 ( 19-CHa). Anal. Calcd. for C31H&: C, 78.42; H, 11.47. Found: C, 78.18; H, 11.81. The diacetate IVb was prepared in pyridine solution with acetic anhydride.
409
3,4-Seco-A8-eburicene-4,24,28-triol-3,21 -dioic Acid (V).-To a solution of 47 mg. of 3,4-se~o-A~~~~(~~~-eburicadien-4-01-3,21-dioic acid (IIa) in 3 ml. of dioxane and 0.2 ml. of pyridine was added dropwise over a 30 min. period a solution of 26 mg. of Os04 in 3 ml. of dioxane. The solution was allowed to remain a t room temperature for an additional hour and then decomposed with HSS. The mixture was filtered over a Celite pad and the filtrate was evaporated to dryness in vacuo. The residue (58 mg.) was recrystallized from ethyl acetate with the aid of Darco G-60 affording glycol acid V, 1n.p. 233-235"; [ a ] D +6S0 ( c 0.47, alco2.95, and 5.85 p ; neut. equiv. 260 (calcd. 263). hol); ;:A: Anal. Calcd. for C31Ha~0~: C, 69.37; H, 9.77. Found: C, 69.45; H, 9.65.
Acknowledgment.-The authors wish to thank the following members of the staff of the Squibb Institute for their contributions to this work: A h . J. Alicino and A h . C. Sabo for the microanalyses, hliss B. Keeler and Miss R. Karitzky for the infrared spectra, A h . W. Bullock for the ultraviolet spectra, Dr. A. Cohen for the n.m.r. spectra, and JIr. H. Rasch for the antibacterial assays.
-
a-
Structures Related to Morphine. XXVI1.l and p-5,9-Diethyl-2-methyl-6,7-benzomorphans ARTHUR E. JACOBSON AND EVERETTE L. MAY Laboratory of Chemistry, Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda 14, Maryland Received March 27, 1964
Sodium borohydride reduction of the dihydropyridine base I1 obtained in the reaction of benzylmagnesium chloride and 3,4-diethylpyridine methiodide has given 2-benzyl-3,4-diethyl-l-methyl-1,2,5,6-tetrahydropyridine (111). This is cyclized by hot hydrobromic acid mainly to a-5,9-diethyl-2-methyl-6,7-benzomorphan (VI) and (as the hydrochloride) by aluminum bromide to a mixture of VI and the p isomer I X as shown by thin film chromatography, Base IX, essentially to the exclusion of VI, resulted from aluminum bromide cyclization of trans-2-benzyl-3,4-diethyl-l-methyl-1,2,3,6-tetrahydropyridine hydrobromide (S'III) also synthesized from I1 via V, IV, and VII. The structure and stereochemistry of I X were proved by ronverting it to the known p-5,9diethyl-2'-hydroxy-2-methyl-6,7-benzomorphan (X). The stereochemistry of both VI and I X was also confirmed by methiodide rate studies. Compounds VI and IX are relatively potent analgesics and VI has no addiction-sustaining capacity in morphine-addicted monkeys.
The analgesically favorable effect of a properly positioned phenolic hydroxyl in structures with a heterocyclic nitrogen (e.g., the morphinans and benzoniorphans)2has been known for some time. However, the role of this substituent in tolerance and physical dependence has not been studied, perhaps because deoxy compounds of the order of potency of morphine have not been a ~ a i l a b l e . ~ The high activity displayed by various 2'-hydroxy-5,9-dialkyl-6,7-benzomorphans, particularly the p-dia~tereomers,~ provided hope that nonphenolic compounds5 of morphine-like potency are not implausible. Furthermore, any such deoxy com(1) Paper X X V I : J. H. Ager, S. E. Fullerton, E. M. F r y , a n d E . L. May, J . OW. Chem., as, 2470 (1963). (2) (a) E. L. h l a y in "Medicinal Chemistry," 2nd Ed., A. Burger, Ed., Interscience, New York, N. Y., 1960, p. 311 et seq.; (b) E. L. M a y and J. H. Ager, J . Org. Chem., 84, 1432 (1959). ( 3 ) N-Methylmorphinan (ref. Za), although one-fifth as potent as morphine and comparable t o pethidine in animal screening tests, has not been further examined. (4) J. H. Ager, S. E. Fullerton, and E. L. M a y , J . Med. Chem., 6, 322 (1963). ( 5 ) Otherwise close congeners of morphine and the morphinans.
pound of possibly negligible addiction liability would not be readily convertible to a product of greater addiction potential, a hazard generally attending hydroxy compounds (viz., conversion of morphine to heroin2& and @-dl-methadol to p-dl-acetylmethad~l~~fj). Consequently, me have synthesized CY- and @-5,9-diethyl-2methyl-6,7-benzoiiiorphans (YI, IX), deoxy compounds selected for study principally on the basis of comparative results reported earlier4in the 2 '-hydroxy series. The synthesis of the a-compound T'1 was achieved, as usual, by the Grewe method,',8 except that sodium borohydride9 was used instead of palladium-catalyzed hydrogen in the reduction of the dihydro base I1 to 2benzyl-3,4-diethyl-l-methyl-l, 2,5,6- tetrahydropyridine (111). Cyclization of 111 with hot hydrobromic acid gave VI in 76% yield. No @-isomerIX could be iso(6) H. Isbell, H. F. Fraser, M. H. Seevers, and G. A. Deneau, private communications. (7) R. Grewe and A. Mondon, Chem. Ber., 8 1 , 2 7 9 (1948). ( 8 ) E. L. M a y and E. SI. Fry, J. Ore. Chem., 22, 1366 (1957). (9) S. E. Fullerton, J. H. Ager, and E. L. May, ibid., 27, 2564 (1962).
