10β-Chloro-17β-hydroxyestra-1,4-dien-3-one and its related compounds

Abstract

Chlorination of steroidal ring A phenols with N-chloro imide reagents (e.g. N-chlorosuccinimide and trichloroisocyanuric acid) afforded the 10β-chloroestra-1,4-dien-3-one (2) together with a smaller proportion of 2,4,10β-trichloroestra-1,4-dien-3-one (3), 2,10β-, and 4,10β-dichloroestra-1,4-dien-3-one [(3) and (5)]. In contrast with the results of bromination using N-bromo imide reagents, only substitution of aromatic ring A was observed. The structure of compound (2b) was established by an X-ray diffraction study. Compounds (2a) and (2b) were readily reduced to the original phenol, and compound (2a) underwent dienone–phenol rearrangement with acetic anhydride–sulphuric acid to yield 4-chloroestra-1,3,5(10)-triene-1,17-diyl diacetate (7).