Cyclodextrin as a Macrocyclic Monomer: Cationic Ring‐Opening Polymerization of O‐Permethylcyclodextrins

It has been disclosed for the first time that a cyclodextrin (CD) derivative is able to act as a macrocyclic monomer for ring‐opening polymerization to produce linear polyglucan. O‐Permethylated α‐, β‐, and γ‐CDs were found to be polymerizable with the aid of a cationic initiator, e.g., Et₃O⁺PF₆^– in dichloromethane. Interestingly, the more strained monomer (α‐ > β‐ > γ‐CD) was less reactive, which is ascribable to the characteristic shape of the CD molecule.