STEROIDS .356. SYNTHESIS OF (19E)-3,20-DIOXOPREGN-4-EN-19-AL 19-(O-CARBOXYMETHYL)OXIME

Hydride reduction of the ketone I gave the (20R)-hydroxy derivative II. Cleavage of the diacetate III with zinc dust, followed by mild Jones' oxidation led to the aldehyde V. Oximation with (O-carboxymethyl)hydroxylamine hemihydrochloride and methylation with diazomethane afforded the ester VI. Alkaline hydrolysis to the acid VII, followed by methylation yielded the diol methylester VIII which on Jones' oxidation and acid catalyzed rearrangement afforded the dione IX. Mild hydrolysis gave the desired hapten X derived from progesterone.