In 60 ml of acetone is dissolved 1.0 ml of n-octanoic acid, and 3.0 ml of 2N-NaOH, 15 ml of water and 1.8 g of 16β-ethyl-17β-bromoacetoxy-4-estren-3-one are serially added to the above solution. The mixture is refluxed for 4 hours. The solvent is distilled off under reduced pressure and the residue is extracted with 150 ml of ethyl acetate. The organic layer is separated, washed with water and saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent is then distilled off under reduced pressure and the residue is subjected to column chromatography. Following passage of 50 ml of diisopropyl ether, elution is carried out with 300 ml of the same solvent. The eluate is evaporated under reduced pressure to remove the solvent, giving 1.7 g of the above-identified compound as a colorless oil.
