Abstract A group of Δ 4-3-keto steroids was prepared by catalytic reduction of suitable conjugated diene-3-keto precursors with tritium gas. Thus, 11α-hydroxy-4-pregnene-3, 20- dione-7-3 H (I), 20α-hydroxy-4-pregnen-3-one-7-3 H (II), 6α-methyl-4-pregnene-3, 11, 20- trione-7-3 H (III), 17α-hydroxy-6α-methyl-4-pregnene-3, 20-dione-7-3 H, acetate (IV), and 17α-hydroxy-6-methyl-3 H 3-16-methylenepregna-4, 6-diene-3, 20-dione, acetate (V) ...
