SYNTHESIS OF 11-KETO-△⁹-NORETHISTERONE

We have introduced a carbonyl group at the 11-position and a double bond at the 9-position of norethisterone in order to increase its antifertility potency. The starting material for the preparation of 11-keto-Δ⁹-noret-histerone(9) was 19-hydroxy-Δ⁴-androstene-3,17-dione(1), which was converted to the title compound by partial synthesis through the sequence of reactions:(1)→(9).11-Keto-Δ⁹-norethisterone was found to possess very potent antifertility effect by preliminary screening tests.