18-Norpregna-8,11,13-trienes. Part 2. Preparation from 17β-methyl-17α-pregn-13-enes

Abstract

17,17-Dimethyl-18-nor-5β-androsta-8,11,13-trien-3α-yl acetate (6) has been prepared from 9α,11α-epoxy-17α-methyl-5β-androstane-3α,17β-diol 3-acetate (5) in good yield. An attempt to repeat the aromatisation with the analogous 9α,11α-epoxy-5β-pregnane-3α,17α,20β-triol 3,20-diacetate (10) did not give the expected product. However, a number of ring-C-aromatic pregnanes have been successfully prepared from derivatives of 5β-preganane-3α,11β,17α,20β-tetraol (21). Attempts to aminate some of these aromatic pregnanes at the 3- and 20-positions are described.