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Non-natural 14-hydroxy steroids. II. 13 alpha,14 alpha and 13 beta,14 beta isomers of methyl
1Laboratoire de chimie structurale, Université de Sherbrooke, Québec, Canada.
Abstract:
C20H24O6, Mr = 360.41 lambda (Cu K alpha) = 1.54056 A, room temperature. (I) (5 beta,10 beta,13 alpha,14 alpha)-Methyl 14-hydroxy-1,7,17-trioxoandrost-8-ene-19-oate, triclinic, P1, a = 7.9514 (5), b = 9.2892 (5), c = 12.8534 (12) A, alpha = 81.256 (6), beta = 75.796 (6), gamma = 77.908 (5) degrees, V = 894.85 (11) A3, Z = 2, Dx = 1.338 Mg m-3, mu = 0.77 mm-1, F(000) = 383.96, final R = 0.043 for 2912 observed reflections. (II) (5 beta, 10 beta, 13 beta,14 beta)-Methyl 14-hydroxy-1,7,17-trioxoandrost-8-ene-19-oate, monoclinic, P21/n, a = 12.8704 (9), b = 10.4481 (9), c = 13.1482 (5) A, beta = 104.103 (5) degrees, V = 1714.77 (20) A3, Z = 4, Dx = 1.396 Mg m-3, mu = 0.81 mm-1, F(000) = 767.92, final R = 0.055 for 2516 observed reflections. These two non-natural steroids bear a methoxycarbonyl group at C(10). In both molecules the relative stereo-chemistry is cis for the A/B ring junction and cis for the C/D ring junction. The relative orientations of MeO2C--C(10) and HO--C(14) are anti for (I) and syn for (II). The methoxycarbonyl group lies at the axial position for (I) and equatorial for (II), relative to ring A. The energies of possible conformations for (I) and (II) are evaluated, wherein the A rings adopt a chair conformation.