Study of the stereoselectivity of 2-azido-2-deoxygalactosyl donors: relationship to the steric factors of glycosyl acceptors.

The stereoselectivity of a 2-azido-2-deoxygalactosyl (GalN(3)) donor is found to strongly depend on the nature of the acceptors in glycosylation reactions. The order of the acceptor, the stereochemistry, and the configuration of the monosaccharide all affect the stereochemistry outcome. More reactive acceptors are observed to favor β-products, while less reactive acceptors afford more α-products.