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.