Kinetics and mechanism of oxidation of unsaturated acids by quinolinium dichromate

The kinetics of oxidation of unsaturated acids (acrylic and methacrylic acids) by quinolinium dichromate in sulphuric acid was studied by following the disappearance of Cr(VI). The rate of the reaction was dependent on the first powers of the concentrations of each reactant-substrate, oxidant and acid. The reaction was suggested to proceed via an intermediate wherein a spectator oxo group could be converted into an oxo triple bond. Rearrangement of this complex resulted in the formation of a cyclic chromate ester, which underwent oxidative decomposition to give the products.