Oxidation of threose-series, pentose and hexoses by N-arylbromosulphonamides in alkaline medium

Shashikala, V. and Rangappa, K. S. (2002) Oxidation of threose-series, pentose and hexoses by N-arylbromosulphonamides in alkaline medium. Indian journal of chemistry section b organic chemistry including medicinal chemistry, 41 (9). pp. 1907-1914. ISSN 0975-0983

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Abstract

Kinetic studies of the oxidation of -galactose, -sorbose and -xylose by bromamine-T (sodium-N-bromo-p-toluenesulphonamide or BAT) and bromamine-B (sodium-N-bromobenzene sulphonamide or BAB) in alkaline medium has been investigated at 303 K. The rate of the reaction is first order both with respect to oxidant and sugar, and second order with respect to [HO-]. The addition of the reaction product p-toluenesulphonamide (PTS) or benzenesulphonamide (BSA) and the variation of ionic strength of the medium have no effect on the rate. The rate decreases with the decrease in dielectric constant of the medium and values of dAB, the size of activated complex are calculated. Proton inventory studies in H2O - D2O mixtures suggest a single transition state. Product analysis for -galactose, -sorbose and -xylose reveal that hexoses give mainly mixture of lyxonic and threonic acids with minor proportions of hexonic, xylonic and glyceric acids, whereas xylose yields a mixture of lyxonic, threonic and glyceric acids with minor amounts of xylonic and hexonic acids. From the results of kinetic studies, reaction stoichiometry and product analysis, a possible mechanism for the oxidation of threose-series sugars is suggested.

Item Type:	Article
Subjects:	C Chemical Science > Chemistry
Divisions:	Department of > Chemistry
Depositing User:	Manjula P Library Assistant
Date Deposited:	26 Sep 2019 07:57
Last Modified:	26 Sep 2019 07:57
URI:	http://eprints.uni-mysore.ac.in/id/eprint/8549

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