FeCl3-catalyzed alpha-glycosidation of glycosamine pentaacetates.

An efficient method for the large-scale preparation of alpha-N-acetylglycosaminides, such as fluorogenic T(N)-antigen probes and an alpha-GalNAc-Ser derivative, has been achieved using FeCl(3)-catalyzed one-step condensation between commercially available D-glycosamine pentaacetates and fluorogenic acceptors (or serine acceptor) in refluxing 1,2-dichloroethane. Experimental simplicity, high alpha-stereoselectivity, low cost, satisfactory yield, and the environmentally benign nature are major advantages of our approach.