SYNTHESIS OF NOVEL 6-AZA-B-HOMOESTRANES AND 11-AZA-C-HOMOESTRANES AS ANTIFERTILITY AGENTS

Reaction of 3,9alpha,17beta-trihydroxyestra-1,3,5(10)-trien-11-one 17-acetate 3-methyl ether (3) with N3H-BF3 etherate leads mainly to lactam (4) along with the N-azido compound (5) as a minor product. Under similar conditions, 3,17beta-dihydroxyestra-1,3,5(10)-trien-6-one 17-acetate 3-methyl ether gives lactam (12) and the tetrazolo derivative (9). Similar reaction of the diacetate (8) gives only the tetrazole derivative (11). Compounds 4, 6, and 10 prevent implantation in rats at 5-, 10-, and 5-mg/kg doses, respectively. Compounds 4, 6, 9, and 10 show significant estrogenic activity at the respective contraceptive doses.