Patent ID: 7485718

Claim:
A process for forming a glycosidic linkage between two hexoses, comprising: i. providing a protected thioglycoside donor and a suitably protected glycosyl acceptor, both of which are hexoses; ii. activating the thioglycoside donor using as activating agents an N-haloimide and at least about a 0.5 molar equivalent amount, to the glycosyl acceptor, of a perfluoroalkyl sulfonic acid in the presence of said acceptor; and iii. reacting the thioglycoside donor and glycosyl acceptor at a temperature from about -20° C. to about -70° C.; wherein the thioglycoside and the glycosyl acceptor form a beta glycosidic linkage; wherein the protected thioglycoside donor has the formula: wherein R 1 and R 2 are each independently selected from H and C 1 to C 20 alkyl, aryl, and aralkyl groups; R 3 and R 4 are each independently selected from monofunctional acyl, bifunctional acyl, phthaloyl, trichloroacetyl, and tetrachlorophthaloyl groups; and R 5 , R 6 , R 7 and R 8 are each independently selected from C 1 to C 20 alkyl, aryl, and aralkyl groups.