17.beta.-ethynyl-3,17.alpha.-estradiol and derivatives thereof are prepared by epimerization of 17-acyl esters of 17.alpha.-ethynyl-3,17.beta.-estradiol 3-ethers. 17.alpha.-ethynyl-3,17.alpha.-estradiol and its derivatives are active as post-coital antifertility agents and inhibit the growth of or reduce the size of the prostate gland and the seminal vesicle.
17-beta-
乙炔基-3,17-alpha-
雌二醇及其衍
生物是通过将17-
乙炔基-3,17-beta-
雌二醇3-醚的17-酰基酯进行对映异构化制备的。17-alpha-
乙炔基-3,17-alpha-
雌二醇及其衍
生物作为事后
避孕药剂活性,并且能抑制前列腺和精囊的生长或减小其大小。