The reaction of 17beta-hydroxy-17-methylandrost-4-en-3-one (I) with thiophenol (A) and formaldehyde by means of triethylamine in refluxing ethanol gives 17beta-hydroxy-17-methy-4-(phenylthiomethyl)androst-4-en-3-one (II), which is desulfurized by treatment with Raney-Ni in water yielding 17beta-hydroxy-4,17-dimethylandrost-4-en-3-one (III). The reaction of (III) with methyl formate by means of sodium methoxide in methanol affords 17beta-hydroxy-4,17-dimethyl-2-hydroxymethyleneandrost-4-en-3-one (IV), which by cyclization with hydroxylamine in acetic acid-sodium acetate is converted into 4,17-dimethylandrosta-2,4-dieno[2,3-d]isoxazol-17beta-ol (V). The epoxidation of (V) with m-chloroperbenzoic acid in methylene chloride gives 4alpha,5alpha-epoxy-4,17-dimethylandrost-2-eno [2,3-d]isoxazol-17beta-ol (VI), which is finally isomerized by treatment with sodium methoxide in THF.

The reaction of 17beta-hydroxy-17-methylandrost-4-en-3-one (I) with thiophenol (A) and formaldehyde by means of triethylamine in refluxing ethanol gives 17beta-hydroxy-17-methy-4-(phenylthiomethyl)androst-4-en-3-one (II), which is desulfurized by treatment with Raney-Ni in water yielding 17beta-hydroxy-4,17-dimethylandrost-4-en-3-one (III). The reaction of (III) with methyl formate by means of sodium methoxide in methanol affords 17beta-hydroxy-4,17-dimethyl-2-hydroxymethyleneandrost-4-en-3-one (IV), which by cyclization with hydroxylamine in acetic acid-sodium acetate is converted into 4,17-dimethylandrosta-2,4-dieno[2,3-d]isoxazol-17beta-ol (V). The epoxidation of (V) with m-chloroperbenzoic acid in methylene chloride gives 4alpha,5alpha-epoxy-4,17-dimethylandrost-2-eno [2,3-d]isoxazol-17beta-ol (VI), which is finally isomerized by treatment with sodium methoxide in THF.