Kinetics and mechanism of the oxidation of acetylacetone by permanganate ionn

The kinetics and mechanism of permanganate ion oxidation of acetylacetone (Acac) was studied in acidic and alkaline media. The rate constants for keto, enol, and enolate anions were determined and discussed. Delocalization of the pi-electrons of the double bond by conjugation results in a slower oxidation rate of enol than can be usually observed for unsaturated compounds. in the case of the keto form, the acid-catalyzed nucleophilic attack of permanganate ion occurs on the carbonyl-C atom. For enolate anion a mechanism with basis-catalyzed electron abstraction is suggested. (c) 2006 Wiley Periodicals, Inc.