Synthesis and characterization of cyclomaltoheptaose (Z)-2-butenedioic monoesters

The reactions of cyclomaltoheptaose (β-cyclodextrin) and maleic anhydride were investigated, and the resulting products characterized by i.r., proton, and carbon-13 n.m.r. spectroscopy. The 13 C-n.m.r. spectra show preferential esterification at HO-6 under various conditions of temperature and concentration of reactants and of catalyst. An increase of temperature, catalyst concentration, or initial molar ratio of maleic anhydride to cyclodextrin increases the rate of esterification.