Starting from ketones 5as and 5c, 8 the dienones 7a and 7c were prepared as described in Scheme I. 9 When these compounds were hydrogenated with Wilkinson's catalyst at 28 psi, the desired trans-fused bicyclic ketones la and IC were isolated in about 80% yield. Small quantities (45%) of partly hydrogenated products were formed, and no cis-fused reduction products could be detected. Hydrogenation of 5c with Pd/C gave 1: l mixtures of cis-and ...
