19-hydroxy steroids. V. 3 ,7 ,19-Trihydroxy-5-androsten-17-one 3,19-diacetate: a potential precursor in the biosynthesis of B-ring unsaturated estrogens

A possible biosynthetic pathway is presented for the formation of B-ring unsaturated estrogens in mammals in which 7α,19disubstituted androgens are postulated as potential intermediates. Attempts to prepare such compounds by rearrangement of Δ⁶-5α-hydroperoxides prepared by photosensitized oxygenation of Δ⁵-19-hydroxy androgens failed. However, treatment of the corresponding allylic alcohols under mild acid conditions led to the formation of the desired 7α-substituted Steroids stereospecifically and in high yield.