Regioselective schiff's base mediated deglycosidation of digitalis glycosides. New efficient synthesis of digoxigenin bis-digitoxoside and digoxigenin mono-digitoxoside

Dialdehydes derived from digoxin glycosides via sodium periodate oxidation were regioselectively deglycosylated by various amino acids in anhydrous methanolic solution to afford excellent yields of digoxigenin bis-digitoxoside and digoxigenin mono-digitoxoside in a single step.