Chromic acid oxidation of hexitols in the presence of 2,2′-bipyridyl catalyst in aqueous micellar media: A kinetic study

Best combination of promoter and micellar catalyst for the rapid conversion of sorbitol to glucose

Kinetic data for oxidation of D-sorbitol to glucose by hexavalent chromium in aqueous medium and aqueous surfactant medium (SDS, TX-100) have been reported. Effect of promoter such as PA, bipy and phenanthroline on the reaction has been investigated. The reaction is performed under pseudo first order condition with an excess of substrate over the oxidant. The reaction is first order with respect to substrate and oxidant. The micelles have a catalytic effect on the reaction. Combination of phen and TX-100 produces almost twelve times increase in rate of oxidation.

Combination of Best Promoter and Micellar Catalyst for Chromic Acid Oxidation of D-Mannitol to Mannose in Aqueous Media

Chromic acid oxidation of D-mannitol to mannose has been studied in aqueous media. The effect of promoter (PA, phen and bpy), micellar catalyst (SDS, TX-100 and CPC) and their combination is studied. All the reactions were performed under the condition [D-mannitol]T ≫ [Cr(VI)]T. All the promoters accelerate the reaction rate and the rate is highest in presence of phen. In absence of a promoter the anionic surfactant SDS increases the rate followed by Triton TX-100. The cationic surfactant CPC retards the reaction in comparison to the reaction in aqueous media. Although phen is the best promoter in absence of any surfactant the catalyst combination of bpy and SDS produce a maximum rate enhancement.