Novel tandem rearrangement of a steroidal ring Dcycloadduct derived from 2-chloroacrylonitrile

Abstract

The cycloadduct 2 derived from reaction of 3-methoxyestra-1,3,5(10), 14, 16-pentaen-17-yl acetate 1 with 2-chloroacrylonitrile undergoes a tandem reaction sequence in the presence of alkali, leading to (16¹R)-3-methoxy-17-oxo-15β, 16¹-cyclo-14, 16β-ethano-14β-estra-1,3,5(10)-triene-16¹-carbonitrile 4, the X-ray crystal structure of which is reported; compound 4 is converted into new ring D bridged analogues of estrone.