Abstract
3β-Acetoxy-6, 19-dioxo-5α-steroid (II) was found to rearrange, under acidic conditions, into 1β, 4β-oxido-A-homo-19-nor-Δ5(10)-6-oxo-steroid (III), and in alkaline medium, into 3β, 6α-dihydroxy-5α-steroid-19-oic acid, 3, 19-lactone (XV). Possible reaction mechanisms involving the same intermedial 3β, 19-hemiacetal of initially formed 3β-hydroxy-6, 19-dioxo-5α-steroid (IV) were proposed. Anisotropic effects of 19-formyl and 3β, 19-lactone carbonyl groups on the chemical shift of 18-methyl protons were also discussed.
