| 摘要 |
The synthesis of 25-hydroxycholesterol from animal bile starting materials in which hyodeoxychloic acid or an ester thereof is converted to the 3 beta -hydroxy-5-cholenic acid alkyl ester, and then converted to 3 beta -hydroxy-25-cyano-5-cholene by a series of steps in which the sterol nucleus is stablized by use of a 3 alpha ,5 alpha -bridge sometimes called an i-steroid configuration, and the carbon chain then extended from the carbon at the 24-position to a cyanide group at the 25-position. The compound so formed is subjected to a series of reactions by which it is transformed into 25-hydroxy-7-dehydrocholesterol which may then be irradiated with ultraviolet light to 25-hydroxycholecalciferol. The invention discloses new and improved processes for preparing these end products and also the compounds formed as intermediates and processes for preparing these intermediates.
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