Two methods for stereoselective b-glycosylation of digitoxose were developed. The first achieved stereocontrol by a 1,3-participation of a N-methylurethane group under acid catalysis. The second utilized mercuric-ion catalyzed cleavage of thioglycosides and a 1,3-participation of ap-methoxybenzoyl group in a neutral medium. The first highly stereoselective and quite eficient synthesis of digitoxin (C7) was achieved by a combination of these methods. The furyl-substituted precursor IV of digitoxigenin (Scheme I) was used as aglycone, and the furan group was converted to the unsaturated lactone of digitoxin by our known oxidation procedure ( M -chloroperbenzoic acid/NaBH,) after the assembly of the carbohydrate portion of the molecule and its deblocking was completed.Introduction. -In previous communications of this series, we have described a novel and efficient methodology for the synthesis of cardenolides, bufadienolides and their analogues. As a result of this technique, we were able to synthesize up to now some 50