One-pot regioselective synthesis of 2(I),3(I)-O-(o-xylylene)-capped cyclomaltooligosaccharides: tailoring the topology and supramolecular properties of cyclodextrins.

The alpha,alpha'-dibromo-o-xylylene cap has been installed at the secondary hydroxyls of a single glucopyranosyl residue in cyclodextrins in one pot and with total regioselectivity; the resulting cyclic ether acts as a removable hinge, allowing selective elaboration of the secondary face and modulating both the self-association and the inclusion capabilities of the hosts.