A process for the preparation of 4-androstene-3,17-dione derivatives of the formula ##STR1## wherein X is 6,7-methylene or fluoro, chloro, or methyl in the 6- or 7-position, comprises fermenting a sterol of the formula ##STR2## wherein X is as above and R.sub.1 is a hydrocarbon residue of 8-10 carbon atoms with a microorganism culture capable of degrading the side chain of a sterol.
一种制备
4-雄烯-3,17-二酮衍
生物的方法,其
化学式为##STR1##其中X为6,7-亚甲基或6-位或7-位为
氟、
氯或甲基,包括利用一种能降解
甾醇侧链的微
生物培养物发酵具有
化学式##STR2##其中X如上所述,R.sub.1为8-10个碳原子的烃基残基。