Stannylene Activation in Glycoside Synthesis: Regioselective Glycosidations at the Primary Position of Galactopyranosides Unprotected in the 2-, 3-, 4-, and 6-Positions

Abstract

(opens in new window) Buy Article (opens in new window) Permissions and Reprints (opens in new window) All articles of this category (opens in new window) Stannylene activation with dibutyltin oxide of methyl D-galactopyranosides and of methyl β -D-glucopyranoside, respectively, followed by glycosidation with 2,3,4,6-tetra- O -benzyl -α -D-glucopyranosyl bromide promoted by tetrabutylammonium iodide, or followed by glycosidation with ethyl 2,3,4,6-tetra- O -benzoyl-1-thio- β -D-glucopyranoside, or ethyl 2,3,4,6-tetra- O -acetyl-2-deoxy-2-phthalimido-1-thio- β -D-glucopyranoside, or ethyl 2,3,4,6-tetra- O -benzoyl-1-thio -α -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 observed in the absence of stannylene activation. oligosaccharides - dibutyltin activation - selective glycosidation