Synthesis of a Potent Antagonist of E-Selectin

A synthesis of an antagonist of E-selectin previously reported by a group at Novartis Pharma in Basel is described. An important feature involves the formation of an ether linkage based on a Rh(II)-catalyzed reaction. Stereocontrolled glycosylations rely on the anomeric activation of 2-pyridylthio carbonate as leaving group for the attachment of beta-D-galactopyranosyl and alpha-L-fucopyranosyl units on a common 1,5-anhydro D-glucitol scaffold.