Stannylene activation with dibutyltin oxide of Me D-galactopyranosides and of Me b-D-glucopyranoside, resp., followed by glycosidation with 2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl bromide promoted by tetrabutylammonium iodide, or followed by glycosidation with Et 2,3,4,6-tetra-O-benzoyl-1-thio-b-D-galactopyranoside, or Et 3,4,6-tetra-O-acetyl-2-deoxy-2-phthalimido-1-thio-b-D-glucopyranoside, or Et 2,3,4,6-tetra-O-benzoyl-1-thio-a-D-mannopyranoside, the latter four glycosyl donors being promoted by dimethyl(methylthio)sulfonium trifluoromethanesulfonate (DMTST), led to regioselective glycosidation at the 6-OH of the stannylene glycosyl acceptors. This selectivity was not obsd. in the absence of stannylene activation. [on SciFinder (R)]