The present invention relates to a process and intermediates for the preparation of 24,24-difluoro-1.alpha.,25-dihydroxycholecalciferol from the readily-available 1.alpha.,3.beta.-dihydroxyandrost-5-en-17-one which is made by a known microbiological process from 3.beta.-hydroxyandrost-5-en-17-one [R. M. Dodson, A. H. Goldkamp and R. D. Muir, J. Amer. Chem. Soc. 82 4026 (1960)].
本发明涉及一种从易得的1α,3β-双羟基雄烯-5-烯-17-酮制备24,24-二
氟-1α,25-二羟基胆
钙化醇的过程和中间体,该中间体通过已知的微
生物学过程从3β-羟基雄烯-5-烯-17-酮制备而成 [R.M. Dodson,A.H. Goldkamp和R.D. Muir,J. Amer. Chem. Soc. 82 4026(1960)]。