Regioselective 2 A -2 D -Disulfonylations of Cyclodextrins for Practical Bifunctionalization on the Secondary Hydroxyl Face

A useful technique to bifunctionalize the secondary hydroxyl faces of cyclodextrins is described. Regioselective2^A,2^D-disulfonylations ofcyclodextrins were achieved by reacting cyclodextrins with a combinationof a novel disulfonyl imidazole reagent and molecular sieves inN,N-dimethylformamide. The resulting disulfonates were convertedto 2^A,3^A,2^D,3^D-dimannoepoxy-cyclodextrins and3^A,3^D-diamino-3^A,3^D-dideoxy-(2^AS,3^AS),(2^DS,3^DS)-cyclodextrins, which contain twofunctional groups on the periphery of the molecules.