Total synthesis of dinordrin and analogues

Abstract

A total synthesis of optically active dinordrin (3c) is detailed, following a flexible and stereoselective route. A number of unexpected and potentially usefull by-products have been identified. The preparation of the novel A-nor-steroid analogues (19), (20), and (21) is also reported. The X-ray crystallographic data of the 11β-hydroxylated tricyclic intermediate (13), the norestr-3(5)-ene-2,17-dione (16b), the alkylated dienedione (8b), and the diethynyldihydroxynorestr-3(5)-ene (21) are reported.