betadex and methylglucoside

Aqueous solutions of D-glucaric acid and model polyols xylitol, methyl alpha-D-glucopyranoside or beta-cyclodextrin were freeze dried, then heated, and the product mixtures analyzed by instrumental methods that included GC-MS, electrospray ionization-mass spectrometry (ESIMS), and NMR. The thermal process and analyses were carried out with these polyols in order to determine to what extent multiple acylations of the alcohol functions occurred with D-glucaric acid lactones serving as acylating agents, the extent to which acylations occurred at the 1 degrees alcohol sites, and the relative tendency for acylations to occur at the C1 or C6 end of the glucaryl unit. The results of these studies showed an overwhelming preference for 1 degrees alcohol acylation and preferred acylation occurring at the C1 end of the glucaryl unit.

Topics: beta-Cyclodextrins; Esterification; Gas Chromatography-Mass Spectrometry; Glucaric Acid; Hot Temperature; Lactones; Methylglucosides; Nuclear Magnetic Resonance, Biomolecular; Spectrometry, Mass, Electrospray Ionization; Starch; Xylitol

When 2,6-di-O-tert-butyldimethylsilylated cyclomalto-oligosaccharides (cyclodextrins) are treated with allyl or methyl iodide and NaH in dry tetrahydrofuran, O-2-->O-3 migration of the secondary 2-O-tert-butyldimethylsilyl groups occurs, leading to 2-O-alk(en)yl-3,6-di-O-tert-butyldimethylsilyl-cyclodextrin derivatives. The detection and identification of the reaction step during which migration occurred is described and possible mechanisms of migration are discussed.

Topics: Acetylation; beta-Cyclodextrins; Carbohydrate Sequence; Cyclodextrins; gamma-Cyclodextrins; Magnetic Resonance Spectroscopy; Methylglucosides; Molecular Sequence Data; Molecular Structure; Organosilicon Compounds