A one-pot synthetic method for the hetero-bifunctionalization of α-cyclodextrin at the secondary hydroxyl side with high clockwise-counterclockwise selectivity

α-Cyclodextrin and 3,3′-benzophenonedisulfonylimidazole in a unimolecular ratio were stirred at 40 °C for 1 h in the presence of a catalytic amount of Cs 2 CO 3 in DMF, and then treated with sodium hydroxide to give 2 A ,3 A -mannoepoxy-2 B -sulfonyl-α-cyclodextrin in 14% isolated yield. The isomer with the reversed saccharide sequence was not detected. The first one-pot synthetic method has been established to ensure the sequence-selective, highly efficient introduction of two different functionalities into the secondary side of α-cyclodextrin.