Convergent synthesis of glycoalkaloids solasonine and its saponin derivative

stereoselective glycosidation of 2-branched trisaccharide trichloroacetimidate donors with steroidal aglycons, in the absence of neighboring group participation; (2) "cyanide effect" mediated regioselective benzoylation of the 4- and 6-hydroxyl groups of galactopyranosyl disaccharide; and (3) an effective approach to prevent orthoester byproduct formation.