betadex and butanesultone

The distribution of substituents in sulfonylbutylethers of cyclomaltoheptaose (beta-cyclodextrin) formed in aqueous medium has been determined by gas chromatography after hydrolysis and formation of the permethylated sulfonylfluoride derivatives. In contrast to other etherification reactions of beta-cyclodextrin, preferred substitution in position 3 of the glucose units has been detected. From 1H NMR and microcalorimetric experiments, the formation of host-guest complexes by beta-cyclodextrin and the reagent 1,4-butane sultone in water became evident. This spatial preorganization presumably favors the reaction with the O-3. In contrast, in methyl sulfoxide preferred 2-O-alkylation was obtained, indicating that host-guest interaction does not influence regioselectivity in this solvent.

Topics: Alkanesulfonates; beta-Cyclodextrins; Calorimetry; Chromatography, Gas; Cyclodextrins; Ethers; Magnetic Resonance Spectroscopy

A method has been developed to determine the distribution of substituents in the glucose units of sulfonylbutylethers of cyclomaltoheptaose (beta-cyclodextrin). This method involves hydrolysis of the glucosidic linkages, permethylation, formation of sulfonylchlorides and subsequent transformation to the permethylated sulfonylfluoride derivatives. The latter were thermostable and could be analyzed by GLC and identified by EI and CIMS. For confirmation, the 2-, 3-, and 6-O-substituted standard compounds were independently synthesized and characterized by NMR and GLC-MS.

Topics: Alkanesulfonates; beta-Cyclodextrins; Carbohydrate Conformation; Chromatography, Gas; Cyclodextrins; Drug Stability; Ethers; Glucans; Indicators and Reagents; Mass Spectrometry; Sulfonic Acids; Thermodynamics