Synthesis of convalloside

The known natural diglycoside convalloside — strophanthidin 3-O-[4-O--d-glucopyranosyl--L-rhamnopyranoside] — has been synthesized. The synthesis was carried out by the Koenigs-Knorr method via the preparation as intermediates of convallatoxin and its 2,3-isopropylidene derivative. Selectivity of glycosylation was achieved by the preliminary protection of the two OH groups in the cardenolide L-rhamnoside (convallatoxin).All-Union Scientific Research Institute of Drug Chemistry and Technology, Khar'kov. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 383–386, May–June, 1988.