Investigation of glycosylating properties of 1-deoxy-1-ethoxysulfonyl-hept-2-ulopyranosyl derivatives. Synthesis of a new sulfonic acid mimetic of the sialyl Lewis X tetrasaccharide

Glycosylation reactions of the ethylthio, bromo and chloro derivatives of 1-deoxy-1-ethoxysulfonyl-hept-2-ulopyranose were studied applying different acceptors under different conditions. Elimination side-reactions affording exo- and endoglycals occured in all cases, however, with different proportions. Glycosyl chloride donor was applied to glycosylate a trisaccharide acceptor obtaining a new sulfonic acid mimetic of the sialyl Lewis X tetrasaccharide in high yield.