3~,16a,l8-Trihydroxyandrost-5-en-17-one and the triacetate of its 16P-epimer have been synthesized from 3phydroxypregna-5,16-dien-ZO-one via the 'hypoiodite' reaction of the derived 3P-acetoxy-1 6a,l7a-epoxypregn-5-en-2O-ols to functionalize C-18, followed by controlled opening of the epoxide ring by reagents chosen to give either 3p,16a,18-or 3p,1 6~,18-triacetoxy-l7a-hydroxypregn-5en-20-one. Reduction of the 20-0x0 group and oxidative cleavage of the C(17)-C(20) bond produced the corresponding 3~,16,18-triacetoxyandrost-5-en-17-one. 3P,16a,18-Trihydroxyandrost-5-en-17one was obtained by deacetylation of its triacetate, but the 16P-epimer rearranged on hydrolysis to give 3~,17~,18-trihydroxyandrost-5-en-16-0ne. The androst-5-ene-3~,16,17p,18-tetraols were also prepared.

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