| 摘要 |
A simple process for preparing 3-( DELTA 4-3-keto-steroid-17 alpha -yl)propionic acid lactones of the androstane series represented by the general partial formula <IMAGE> wherein ABCD represents an optionally substituted cyclopentanophenanthrene steroid molecule skeleton, from corresponding 17 alpha -(3-hydroxypropynyl)-17 beta -hydroxy steroids, comprises reducing the latter to the 17 alpha -(3-hydroxypropenyl)17 beta -hydroxy steroid, effecting ring closure to the lactol, and subsequently oxidizing with chromic acid to the lactone.
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