Production of 7 beta-hydroxy-dehydroepiandrosterone, comprises, e.g. selective oximation and reduction process involving 3-O-acetyl-7-oxo-dehydroepiandrosterone

Production of 7beta-hydroxy-dehydroepiandrosterone (I), comprises: (1) protection of the 17-keto group of 3-O-acetyl-7-oxo-dehydroepiandrosterone (II) using an optionally O-protected hydrazine; (2) reduction of the 7-keto group of the obtained 17-oxime (IV) using alkali metal borohydride; (3) deprotecting the oxime; and (4) deprotecting the obtained 3-O-acetyl compound (V) by transesterification. Production of 7beta-hydroxy-dehydroepiandrosterone of formula (I) comprises: (1) regioselective protection of the 17-keto group of 3-O-acetyl-7-oxo-dehydroepiandrosterone of formula (II) using a hydrazine compound of formula NH2OR (III) in non-complexed form; (2) chemoselective and diastereoselective reduction of the 7-keto group of the obtained 3-O-acetyl-7-oxo-dehydroepiandrosterone 17-oxime of formula (IV) using alkali metal borohydride as reducing agent; (3) deprotecting the oxime; and (4) deprotecting the obtained 3-O-acetyl-7beta-hydroxy-dehydroepiandrosterone of formula (V) by transesterification. R = H, 1-3C alkyl, butyl, tert. butyl (optionally substituted benzyl (specifically 2-chlorobenzyl)), CH2SPh, SiMe3 or SiMe2tBu. L'invention se rapporte à un nouveau procédé de préparation de la 7béta-hydroxydéhydroépiandrostérone de formule (1) :