Preparation of 7-[O-(Carboxymethyl)oxime] Derivatives of Dehydroepiandrosterone and Pregnenolone

Abstract

Novel simple syntheses of 7-(O-carboxymethyloxime) derivatives of 3β-hydroxyandrost-5-en-17-one (dehydroepiandrosterone) and of 3β-hydroxypregn-5-en-20-one (pregnenolone) are reported. In the first one, 17-oxoandrost-5-en-3β-yl acetate was oxidized to give the 7,17-dione which was then selectively reduced in the position 17. Oximation, reoxidation, and deacetylation yielded the desired oxime. The second synthesis started with (20R)-pregn-5-ene-3β,20-diol 3-acetate which was converted to the 20-nitrate, oxidized to the C-7 ketone, oximated, partially deprotected in position 20, reoxidized, and deacetylated. Both the 7-(O-carboxymethyloxime) derivatives have been devised as immunoassay components.