Partialsynthesen von Cardenoliden und Cardenolid‐Analogen. III. Synthese von Cardenolid‐analogen β‐Steroidyl‐crotonsäuremethylestern

Abstract

Partial Syntheses of Cardenolides and Cardenolide Analogues. III. Synthesis of Cardenolide‐Analogous Methyl β‐Steroidyl‐crotonates Starting with 14‐hydroxy‐5β, 14β‐pregnan‐3β‐yl‐acetate ( 2 ) the synthesis of the cardenolide analogues methyl 3β‐acetoxy‐14, 15β‐epoxy‐24‐nor‐5β, 14β‐chol‐20(22)‐en‐23‐oate ( 7 ) via Reformatskij synthesis and methyl 3β, 14‐dihydroxy‐5β, 14β‐chol‐20(22)‐en‐23‐oate ( 11 ) via addition of lithium ethoxyacetylide to 2 are described. The activity of 11 in the ATPase‐test is about the same as that of digitoxigenin.