Syntheses of Confertifolin, Winterin and Isodrimenin Congeners From Podocarpic Acid

Abstract

Podocarpic acid (11) has been converted into the congener (5) of confertifolin (4) through the o-quinone (29) formed by oxidations of the catechol monoether (15) and the 13-amine (16) with Fremy's salt. Oxidation of the methyl ether (12) afforded the p- quinone (44) which was converted into the congener (6) of winterin (7). Podocarpic acid has also been converted into the congener (8) of isodrimenin (9) through the catechol derivative (37).