Synthesis of (19E)-3 beta,17-dihydroxy-20-oxopregn-5-en-19-al 19-(O-carboxymethyl)oxime, new steroidal hapten for 17-hydroxypregnenolone.

A synthesis of (19E)-3 beta,17-dihydroxy-20-oxopregn-5-en-19-al 19-(O-carboxymethyl)oxime (15), is reported. Hydride reduction of ketone 1 gave the (20R)-hydroxy derivative 2 as the main product. Formylation of 2 followed by cleavage of the epoxide ring and mild Jones oxidation afforded aldehyde 6. Oximation with (O-carboxymethyl)hydroxylamine and subsequent methylation yielded methyl ester 8 which was selectively hydrolyzed to alcohol 9 and oxidized to ketone 10. Enolacetylation, epoxidation, and hydrolysis led to the desired 19-(O-carboxymethyl)oxime derivative of 17-hydroxypregnenolone 15.