HYDROLYSIS OF (2-DEOXY-BETA-D-GLUCOPYRANOSYL)PYRIDINIUM SALTS

被引：57

作者：

HUANG, XC ^{[1
]}

SURRY, C ^{[1
]}

HIEBERT, T ^{[1
]}

BENNET, AJ ^{[1
]}

机构：

[1] SIMON FRASER UNIV,DEPT CHEM,BURNABY,BC V5A 1S6,CANADA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1995年 / 117卷 / 43期

关键词：

D O I：

10.1021/ja00148a002

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The hydrolysis reactions of three (2-deoxy-beta-D-glucopyranosyl)pyridinium salts exhibit first-order rate constants that are independent of pH in the range of 4.4-10.1 pH units. Derived second-order rate constants for the hydrolysis reactions of (2-deoxy-beta-D-glucopyranosyl-4'-bromoisoquinolinium bromide (5b) conducted in the presence of nucleophilic monoanions (mu 2.0) including AcO-, Cl-, Br-, and N-3(-) exhibit a Swain-Scott parameter (s) of 0.03 +/- 0.05, indicating that these reactions show no sensitivity to the nature of the anion. However, a substantial quantity of the (2-deoxyglucopyranosyl)pyridinium salt hydrolysis product is formed as a result of a post-rate-limiting reaction involving a nucleophilic anion. Analysis of the product ratios indicates that the first-formed intermediate in the hydrolytic reaction is a solvent-separated ion pair:molecule encounter complex. The data allow a calculated estimate of greater than 2.5 x 10(-12) s for the lifetime of the glucopyranosyloxocarbenium ion in aqueous solution,

引用

页码：10614 / 10621

页数：8

共 30 条

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