Synthesis of meiosis-activating sterols containing fluorine

It is documented that specific types of sterol play a major role in the resumption of meiosis in oocytes from mice in vitro. 4,4-Dimethyl-5 alpha-cholesta-8,14,24-trien-3 beta-ol (FF-MAS) isolated from human follicular fluid and 4,4-dimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol (T-MAS) isolated from bull testicular tissue, have been shown to activate (promote) meiosis in vitro. In order to evaluate the biological activity and stability of such compounds, new demethylsterol derivatives have been synthesised. Using diethylaminosulfur trifluoride (DAST) it was possible to synthesise selected delta 8, delta 14 sterols with mono and difluoro substitution at C3.