Protecting Group Free Glycosidations Using p -Toluenesulfonohydrazide Donors

N'-Glycopyranosylsulfonohydrazides are introduced as glycosyl donors for protecting group free synthesis of O-glycosides, glycosyl azides, and oxazolines. Mono- and disaccharides containing a reducing terminal N-acetylglucosamine residue were condensed with p-toluenesulfonylhydrazide to give the desired beta- d-pyranose donors. These donors can be activated with NBS and then glycosidated with the desired alcohol or transformed to the oxazoline or glycosyl azide.