ChemInform Abstract: A READY CONVERSION OF A PREGNANE‐20‐CARBOXALDEHYDE TO 17α‐HYDROXYPREGNAN‐20‐ONES AND PREGN‐16‐EN‐20‐ONES

Abstract

Der aus Stigmasterin in 70proz. Ausb. erhältliche Aldehyd (I) geht beim Behandeln mit O2/K‐tert.‐butoxid und Trimethylphosphit in ein Gemisch der Alkohole (II) und (III) über.

Steroids: reactions and partial syntheses

“…88 A pregnane-20-carboxaldehyde may be converted directly into the 17a-hydroxy-20-ketone by sequential treatment with O2 plus ButOK and then (MeO),P, and treatment of a A1 7(20)-pregnene-20-carboxaldehyde with 0 2 , KOH, DMF, and ButOH gave the A16-20-ketone. 189 Treatment of cyclic 17,21 -orthoesters with xanthene-9carbonyl chloride gave the 2 1 -chloro-17-acyloxy-compounds directly. 90 Elimination of nitrate esters of 17a-hydroxy-20-0~0compounds with LiCl in HMPA affords the Al6-20-ox0compounds; the reaction of 21 -mesyloxy-20-oxo-9~, 17a-diyl nitrates under the same conditions affords the 21 -chloro-20-O X O -A ~( ~ ), 6-compounds directly.…”