C(O[C@H:5]1[CH2:22][CH2:21][C@@:20]2([CH3:23])[C:7](=[CH:8][CH2:9][C@@H:10]3[C@@H:19]2[CH2:18][CH2:17][C@@:15]2([CH3:16])[C@H:11]3[CH2:12][C:13]([CH3:28])=[C:14]2NC(=O)C)[CH2:6]1)(=O)C.[OH2:29].Cl.C(CC(C)(C)C)(C)C.C(OCC)(=O)C>C1COCC1>[CH3:28][C@H:13]1[CH2:12][C@H:11]2[C@H:10]3[C@H:19]([CH2:18][CH2:17][C@:15]2([CH3:16])[C:14]1=[O:29])[C@:20]1([CH3:23])[C:7]([CH2:6][CH2:5][CH2:22][CH2:21]1)=[CH:8][CH2:9]3The crude methyl enamide acetate (3, 1.94 g) was refluxed in 100 ml each of THF and water with 10 ml of concentrated HCl for 31/2 hours. Following the usual work-up the crude hydroxy methyl ketones (5 and 6) were converted to the 3-acetates. Silica gel thin layer chromotography using isooctane-ethyl acetate (21:4) roughly showed a 3:1 mixture of polar (Rf 0.17) and mobile (Rf 0.21) products, representing a mixture of the 16α-methyl and 16β-methyl-17-ones, respectively. Crystallization of the original 3-hydroxy mixture gave 425 mg of pure 16β-methyl-5-androsten-17-one (6), mp 168°-170°. The mother liquor residue (660 mg) represented a mixture of 16α and 16β-methyl-3-hydroxy-17-ones (5 and 6).
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