Abstract
Isomeric 15α- and 17α-bromo-13α-estratrien-16-ones (IX, X) were prepared from the parent 16-ketone (VII) by way of the enol acetate (VIII). The configuration of both bromine atoms introduced was determined by the standard method of Fieser and Ettorre. These positional isomers were readily distinguished by converting into the ⊿15- and ⊿16- unsaturated compounds (XIII, XIV), respectively. On the basis of the spectral data listed in Table I the nature of C-bromine bonds and the conformation of ring D have been discussed. Two synthetic routes leading to the 17α-acetoxy-16-ketone (V) have also been described.
