Partialsynthesen von Cardenoliden und Cardenolid‐Analogen. IX. Cardenolidderivate mit einer ungesättigten Aldehydfunktion am Lactonring

Partial Syntheses of Cardenolides and Cardenolide Analogues. IX. Cardenolide Derivatives with an Unsaturated Aldehyde Function at the Lactone Ring Oxidation of 22‐allyl‐digitoxigenin‐3‐acetate [1] and 22‐allyl‐digitoxin (4) with selenium dioxide resulted in the introduction of an oxygen function into the unsaturated C‐22 substituent of the cardenolide molecule. The isolated compounds were the 22‐(3′‐oxo‐prop‐1′‐en‐1′‐yl)‐derivatives 3 and 6 of 1 and 4, respectively. The molecular biological activity of 3 was estimated to be about six times higher than that of the parent compound 1.