Relative reactivities of 1,2-dicarbonyl compounds towards permanganate in ethanoic acid medium. Mechanism of the oxidation processes

The oxidative behaviour of the 1,2-dicarbonyl compounds, viz., glyoxal, bia cetyl and benzil, towards permanganate in ethanoic acid medium in the prese nce of HClO4 has been investigated. The reaction is first order with respec t to MnO4-, substrate, as well as H+. The rate decreases with an increase i n ionic strength. Different thermodynamic parameters have been evaluated. T he protonated dialdehyde or diketone reacts with permanganate ion to form a n intermediate ester which decomposes in a slow step to produce the corresp onding carboxylic acid via C-C bond cleavage.