Synthesis of nitrile derivatives of estrogens

The first time synthesis of 7α- and 11β-nitrile estradiol is described. Reaction of 7α-cyano-19-nortestosterone with copper(II)bromide in acetonitrile at room temperature results in aromatization of the A-ring. Treatment of 11β-cyano-19-nortestosterone-17-one under similar condition does not induce A-ring aromatization but rather results in bromination at the 2β-position. However A-ring aromatized products are obtained when the latter compound is treated with Ac2O-Py-AcOCl, NBS and HCl.