KINETICS AND MECHANISM OF THE OXIDATION OF SOME UNSATURATED ACIDS BY MORPHOLINIUM CHLOROCHROMATE

摘要

The oxidation of maleic,fumaric,crotonic and cinnamic acids by morpholinium chlorochromate (MCC) in dimethylsulphoxide (DMSO) leads to the formation of corresponding epoxide.The reaction is first order with respect to MCC and the acid.The reaction is catalysed by hydrogen ions.The hydrogen-ion dependence has the form:k_(obs) = a + b [H+].The oxidation of these acids was studied in 19 different organic solvents.The solvent effect was analysed by the Kamlet's and Swain's multiparametric equations.Solvent effect indicated the importance of the cation-solvating power of the solvent.A mechanism involving a three-centre transition state has been postulated.