This invention relates to novel 25-hydroxy-24-oxocholestane derivatives and a process for preparing them. The novel 25-hydroxy-24-oxocholestane derivatives of this invention can easily be converted to 24,25-dihydroxycholecalciferol or 1.alpha.,24,25-trihydroxycholecalciferol which is known as useful for medicine controlling the calcium metabolism of warm-blooded animals. Moreover, 25-hydroxy-24-oxocholestane derivatives can be converted to novel 25-hydroxy-24-oxocholecalciferol expressed by the following formula ##STR1## and novel 1.alpha.,25-dihydroxy-24-oxocholecalciferol of the formula ##STR2## which are useful for medicine. The new 25-hydroxy-24-oxocholestane derivatives in the present invention are very useful as the intermediates for the synthesis of a variety of active vitamin D.sub.3.
这项发明涉及新型的25-羟基-24-氧基胆甾烷衍
生物以及其制备方法。本发明的新型25-羟基-24-氧基胆甾烷衍
生物可以很容易地转化为24,25-二羟基胆
钙化醇或1α,24,25-三羟基胆
钙化醇,这在医学上被认为对于控制温血动物的
钙代谢很有用。此外,25-羟基-24-氧基胆甾烷衍
生物可以转化为由以下式表示的新型25-羟基-24-氧基胆
钙化醇和由以下式表示的新型1α,25-二羟基-24-氧基胆
钙化醇,这在医学上很有用。本发明中的新型25-羟基-24-氧基胆甾烷衍
生物非常有用,可作为合成各种活性
维生素D.sub.3的中间体。