494 mg of 3,3-(ethylenedioxy)-11β-[4'-(methylthio)[1,1'-biphenyl]-4-yl]-5-estren-17-one is dissolved in a mixture of 6 ml of tetrahydrofuran, 6 ml of methanol and 2 ml of water and mixed with 924 mg of sodium periodate. The reaction mixture is stirred at room temperature overnight, then filtered on Celite and the filtrate is diluted with ethyl acetate. The organic phase is washed with saturated sodium bicarbonate solution, dried on sodium sulfate and concentrated by evaporation in a vacuum. After chromatography of the residue on silica gel with a mixture of hexane/ethyl acetate, 346 mg of the title compound is obtained as white foam.
