Collect. Czech. Chem. Commun. 1983, 48, 1224-1232

Alternative syntheses of steroidal maleimides

Pavel Drašar, Vladimír Pouzar, Ivan Černý and Miroslav Havel

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


The described synthesis starts from the α-keto esters VIII and XVI which afford the maleimides X and XVIII via products of condensation with carbamoylmethylenetriphenylphosphorane (IX and XVII). In this way, the steroidal maleimides X and XVIII (structurally similar to the cardenolides), derived from 17β-androstanyl-(2-maleimide) and 21-nor-pregnanyl-(2-maleimide) were prepared. Other routes for their preparation have been studied.