25-HYDROXY-24-OXOCHOLESTANE DERIVATIVES AND PREPARATION THEREOF

摘要

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 24,25dihydroxycholecalciferol or 1a,24,2s-trihydroxychole-calciferol which is known as useful for controlling the calcium metabolism of warm-blooded animals. Moreover, 25-hydroxy-24-oxocholestane derivatives can be converted to novel 25-hydroxy-24-oxochole-calciferol expressed by the following formula and novel 1.alpha.,25-dihydroxy-24-oxocholecalciferol of the formula which are useful medicines. The new 25-hydroxy-24-oxocholestane derivatives of the present invention are very useful as intermediates for the synthesis of a variety of active vitamin D3.