Synthesis of a Steroidal Dicarbamate Related to Meprobamate from 3‐Ketobisnorcholenal

Abstract

Condensation of 3‐ketobisnorcholenal (1) with malononitrile could be directed selectively to the aldehyde group to afford dicyanomethylene ketone 3. Ketalization of 3 with ethylene glycol followed by alkaline hydrolysis gave the aldehydo dioxolane 5, which served as starting material for the syntheses of 1,3‐propanediol derivatives 7 and 10 and their respective dicarbamates 9 and 11.