Steroid [16, 17-c]isoxazoline

Abstract

5'-Methyl-5α-androstano[16, 17-c]isoxazolin-3β-ol (Va) and 5'-methylandrost-5-eno[16, 17-c]isoxazolin-3β-ol (Vb), were obtained by treatment of 3β, 20α-dihydroxy-5α-pregnan-16-one 3-acetate 16-oxime (IIIa) or 3β, 20α-dihydroxypregn-5-en-16-one 3-acetate 16-oxime (IIIb) with tosyl chloride in pyridine followed by alkaline hydrolysis. Oxidation of Va and Vb gave the corresponding 3-oxo-compounds, VIa and VIb. VIb was further isomerized to 5'-methylandrost-4-eno[16, 17-c]isoxazolin-3-one (VIIb).