Direct and Regioselective Di-α-fucosylation on the Secondary Rim of β-Cyclodextrin.

A straightforward glycosylation method is described to regio- and stereoselectively introduce two α-l-fucose moieties directly to the secondary rim of β-cyclodextrin. Using NMR and MS fragmentation studies, the nonasaccharide structure was determined, which was also visualized using molecular dynamics simulations. The reported glycosylation method proved to be robust on gram-scale, and may be generally applied to directly glycosylate β-cyclodextrins to make well-defined multivalent glycoclusters.