CORTICOSTEROID INTERMEDIATES. 11. A ROUTE TO 11-OXYGENATED STEROIDS
NEW
droergosterol acetate) (I),' prepared by mercuric acetate dehydrogenation of ergosterol acetate, was .sly: catalytically isoiiierized with liquid sulfur dioxide X new synthetic route has been devised for the in over 80% yield to the C-ring diene A6,8(14),9(11),3"conversion of C-ring unsubstituted steroids to ergostatetraen-30-01 acetate (11)' m.p. 149.0cortisone. In contrast to reeently published meth- 151.0'; [ a ] D -94' (CHC13); Ama=. 287.5 mu (log ods, which involve epoxidation of steroid 7)9(11)- E = 3.82)) Amax 232.5 mu (log e = 4.25) (ether); dienes,' our synthesis ctriploys photocliernical found : C, 82.39; H , 10.26.8 Photoperoxidatiorl" peroxidation of honioannular C-ring dienes to in- of I1 afforded A6~8~22-ergostatrien-3/3-ol acetate [a]D troduce 11-oxygen as an 11,14-peroxide bridge. 11,lA-peroxide (111)) m.p. 164.6-166.4'; The C-ring endoperoxide system undergoes facile -19' (CHC13); A,, 27% mu (log e = 3.61) rearrangement to form directly 11-keto steroids (ether); found: C, 77.03; H, 9.50. Experisuitable for conversion to cortisone. The prepara- mental evidence in support of the structure 111 was tion of the C-ring dienes required in this synthesis obtained by selective hydrogenation over a leadis accomplished by a heretofore unreported isomeri- palladium catalyst to form a glycol, A6,R,?2-ergostnlation of nuclear trienes of the dehydroergosterol trien-3@,1I, 14-triol 3-acetate (VI1I), m.p. 1OO.S type. This communication reports the applira- 163.-k0; [ a ] D -34' (CHC13); Amax 274 Ill11 (log c = 3 . f 3 ) (cthcr); f o u r i d : C ,7Kfil ; TT, 9.75, which t i o i l of the. new synthesis to ergosterol. ,
/
'+,/
OH
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R
=
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I
'
\
I
7 -- I ' ,+/
--
I
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I
.. /
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t-
-CH(CH,)CHICH>CH(CH*)CH(CH )? AcO' J
A5~7~9(11)22-Erg~~tatetraen-3~-01 acetate (dehy(1) L. F. Fieser, J. E. Herz and W. Huang, THIS J O U R N A L , 73, 2397 (1951); L. F. Fieser, J . C . Babcock, J . E. Herz, W, Huang and W. P. Schneider, ibid., 74, 4054 (19.51). (2) (a) E. X. Chamberlin, W. V. Ruyle, A. E . Erickson, J. M. Chemerda, L. M. Aliminosa, R. L. Erickson, G. E. Sita and X I . TishIer, ibid., 73, 2396 (1951); (b) E. Schoenewaldt, L. Turnbull, E. M. Chamberlin, D. Reinhold, A. E. Erickson, R'. V. Ruyle, 5. XI. Chernerda and M. Tishler, ibid., 74, 2696 (1952). (3) (a) G. Stork, J . Romo, G. Rosenkranz and C. Djerassi, ibid., 73, 3546 (1951); (h) F. Sondheimer, R. Yasbin, G. Rosenkranz and C . Djerassi, ibid.. 74, 2697 (1952). (4) H. Heusser, K. Eichenberger, P. Kurath, H. Dallenhach and 0.Jeger, Helo. Chim. Acta, 34, 2106 11951) R. C. Anderson, R. Budziarek, G. T. Newhilld, R . S t e v r n w n and 1'. S. Spring, C h e x a i d I d . , 1035 (1951). (6) P. Rladon, R . B. Clayton. C . W. C,remhdgIi, 11. R Iirnlie.;t, I?. R. IT. Junes, B. J . I,
