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

A synthesis of (19E)-3β,17-dihydroxy-20-oxopregn-5-en-19-al 19-(O-carboxymethyl)oxime ( 15 ), is reported. Hydride reduction of ketone 1 gave the (20-R)-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 .