Acetylation of Secondary Hydroxy Groups of α- and β-Cyclodextrines Silyl Derivatives

摘要

The application of acetyl chloride in the combination with different solvents and bases permitted the preparation of silyl derivatives of α- and β-cyclodextrines containing a definite amount of acetyl substituents on the secondary hydroxy groups. It was found that by means of the ~1H and ~(13)C NMR spectroscopy it is possible to make an exact attribution of acetyl groups to C~2 or C~3 carbon atoms of carbohydrate fragments of α- and β-cyclodextrines. Desilylation with ammonium fluoride in methanol gives acetyl derivatives of cyclodextrines containing free primary hydroxy groups.