Cardiotonic (3)-oxo-proscillaridin A derivs. - prepd. by oxidising (2',4')-diacyl-proscillaridin A derivs.

摘要

New cardioglycoside derivs. are cpds. of formula (I). In this formula, R1 is H, 2-4C aliphatic acyl or aroyl (pref. benzoyl) and R2 is H or is 1-5C acyl opt. substd. by nitrilo, halogen (pref. Cl), 5-6C cycloalkyl, aryl (pref. phenyl or halo- or methyl-substd. phenyl) or ethoxycarbonyl. (I) have good cardiotonic activity. Because of the reactive oxo gp. on the rhamnose residue, they are also useful as intermediates (cf. DT 2504195). Specific cpds. (I) include 2'-(4-cyanobutyryl)-3'-oxo-4'-acetylproscillaridin. In an example, this is prepd. by reacting proscillaridin with triethyl 4-cyano-orthobutyrate and acetic anhydride to give 2'-(4-cyanobutyryl)-4'-acetyl-proscillaridin and dehydrating this with dicyclohexylcarbodiimide and pyridinium chloride.