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Alkylation of cyclomalto-oligosaccharides (cyclodextrins) with dialkyl sulfate-barium hydroxide: Heterogeneity of products and the marked effect of the size of the macrocycle

✍ Scribed by Tetsumi Irie; Kazuhiro Fukunaga; Josef Pitha; Kaneto Uekama; Henry M. Fales; E.A. Sokolowski

Book ID: 102991324
Publisher: Elsevier Science
Year: 1989
Tongue: English
Weight: 397 KB
Volume: 192
Category: Article
ISSN: 0008-6215
DOI: 10.1016/0008-6215(89)85176-6

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✦ Synopsis

The alkylation of cyclomJlto-oligosaccharides (cyclodextrins, CDs) with dialkyl sulfate-barium hydroxide has been claimed to yield 2,6-di-O-alkyl derivatives. Re-investigation by plasma desorption-m.s. of the products of laboratory methylation of (rCD, j3CD, or $D and ethylation of /3CD and several commercial preparations revealed them to be mixtures with broad and roughly symmetrical distributions of the degree of substitution. Recrystallization separated the components only partially. Analysis of the product of methylation of a mixture of CDs established the order of reactivity y 4 (Y 2 p. The reactivity of -yCD thus resembles that of amylose.

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✍ C. Trinadha Rao; Josef Pitha; Bengt Lindberg; Johan Lindberg 📂 Article 📅 1992 🏛 Elsevier Science 🌐 English ⚖ 533 KB

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