Oxidation with permanganate in strong alkaline medium. Oxidation of pyruvic and lactic acids

The reaction of permanganate ion with pyruvic acid and lactic acid has been studied in aqueous solutions containing 0.10–2.0 mol dm^?3 alkali. In this range of HO^? concentration the reaction is followed slowly by the reduction of manganate, thus, the above process can be studied separately. In the case of lactic acid (LA), the reactive species is alkoxy anion, and the deprotonation constant could be calculated from the kinetic data. A mechanism based on electron abstraction from the alkoxy anion has been proposed. In the case of pyruvic acid (PA) oxidation may proceed with participation of enolate anion, or hydrate anion, or an adduct. These three possibilities have been investigated. © John Wiley & Sons, Inc.