The reactions of estrogens with benzeneseleninic anhydride and hexamethyldisilazane

Abstract

Reaction of estrone and 17-ethynylestradiol with benzeneseleninic anhydride and hexamethyldisilazane gave predominantly the respective 4-phenylselenoimines, together with smaller amounts of the corresponding 2-substituted derivatives. Reductive acetylation of these compounds gave high yields of the 4- and 2-acetamidoderivatives of 3-acetoxyestrone and 3,17-diacetoxy-17-ethylnylestradiol respectively. Under similar conditions 4-bromoestrone gave the 2-phenylselenoimine which was then converted into 2-acetamido-3-acetoxy-4-bromoestra-1,3,5(10)-trien-17-one. This on hydrogenolysis furnished 2-acetamido-3-acetoxyestra-1,3,5(10)trien-17β-ol. A possible mechanistic rationalisation of these results is proposed.