Synthesis of Sialyl Lewis X Mimetics and Related Structures Using the Glycosyl Phosphite Methodology and Evaluation of E-Selectin Inhibition

This paper describes our recent study of glycosyl phosphites for glycosylation reactions, with particular emphasis on the investigation of protecting group and stereochemistry effects on the anomeric reactivity and stereoselectivity, and the application of this methodology to the synthesis of Lewis X (Lex), Lewis Y (Ley), glycopeptides, and sialyl Lewis X (SLex) mimetics. Both α-O-fucosyl-l-threonine and α-O-fucosyl-(1R,2R)-2-aminocyclohexanol were found to be effective templates for the chemical/enzymatic synthesis of SLex mimetics, and some fucopeptides prepared were 5−10 times more active than SLex as inhibitors of E-selectin.