Stereospecific Solution- and Solid-Phase Glycosylations. Synthesis of β-Linked Saccharides and Construction of Disaccharide Libraries Using Phenylsulfenyl 2-Deoxy-2-Trifluoroacetamido Glycopyranosides as Glycosyl Donors1

Abstract

An efficient strategy to construct β-O-2-amino-2-deoxyglycopyranosidic linkages using glycosyl sulfoxides is demonstrated. Phenylsulfenyl 2-deoxy-2-trifluoroacetamido glycopyranosides were found to be reactive glycosyl donors in both solid- and solution-phase glycosylations, affording the corresponding β-glycosides exclusively and in high yield. The trifluoroacetamido group was removed under mild conditions, allowing orthogonal derivatization of multiple protected amino groups on an oligosaccharide or glycoconjugate. On the basis of the results with these glycosyl donors, a solid-phase β-linked disaccharide library was constructed. The scope and flexibility of this approach will be discussed.