Shortcut synthesis of beta-cyclomannin from beta-cyclodextrin.

Beta-cyclomannin, a cyclic oligosaccharide consisting of seven alpha-D-mannosides connected together by the (1-->4) glycoside linkage, has been efficiently synthesized by the OsO4 oxidation of heptakis(2,3-didehydroxy)-beta-cyclodextrin which was prepared from beta-cyclodextrin by a five-step transformation. The novel cyclooligosaccharide not only showed water solubility high enough to meet the requirement for drug formulation but also demonstrated strong binding ability toward guest molecules. [reaction: see text]

Functionalization of cyclodextrins via reactions of 2,3-anhydrocyclodextrins.

Three types of reactions of 2,3-anhydro-beta-cyclodextrins, namely nucleophilic ring-opening, reduction to 2-enopyranose, and reduction to 3-deoxypyranose, have been investigated to regio- and stereoselectively functionalize the secondary face of beta-cyclodextrin. Upon treatment with various nucleophiles, both 2,3-mannoepoxy and 2,3-alloepoxy-beta-cyclodextrins are found to undergo nucleophilic ring-opening reaction generating 3- and 2-modified cyclodextrin derivatives. In each case, the 3-position is more easily accessible than the 2-position.