OXIDATION OF METHYLPENTOSES BY SODIUM N-CHLOROBENZENE SULFONAMIDE IN ALKALINE-MEDIUM - A KINETIC AND MECHANISTIC STUDY

Kinetics and mechanism of oxidation of three methylpentoses, namely D- fucose, L-fucose and L-rhamnose with sodium N-chlorobenzene-sulphonami de (chloramine-B or CAB) in alkaline medium were studied at 313 K. The rate law, rate = k [CAB] [S] [HO-] was observed. Benzenesulphonamide and chloride ions, the reduced products of the oxidant had no effect o n the reaction rate. The rate increased with increase in ionic strengt h of the medium and the dielectric effect was negative. Proton invento ry studies were made in H2O-D2O mixtures. HPLC analysis of products in dicated a mixture of aldonic acids in varying proportions. A mechanism involving the furanosidic ringform of methylpentoses which preferenti ally reacts with CAB in the rate limiting step is suggested.