Molecular rearrangement of 3-substituted 4-chloro-4,5-epoxide systems in ring A of steroids

Abstract

Both stereoisomers of the 3-oxo-, 3-hydroxy-, and 3-acetoxy-4-chloro-4,5-epoxy derivatives of 17β-acetoxyandrostanes have been synthesized, and their thermal rearrangement products have been identified. A synthesis of the diosphenols, 17β-acetoxy-4-hydroxyandrost-4-en-3-one and 17β-acetoxy-4-hydroxyandrosta-4,6-dien-3-one, through a novel rearrangement of the 3-hydroxy- and 3-oxo-4-chloro-4,5-epoxides, respectively, is described. In addition to the chloro ketone products from the 3-acetoxy derivatives, rearrangement and elimination products were also formed. Structural determinations are based upon one- and two-dimensional ¹H and ¹³C n.m.r. correlations and analyses.