Micellar Catalysed Oxidative Decarboxylation of Butyric and Iso-Butyric Acids by Acidine Permanganate Ions

Abstract

A.micellar catalyzed oxidative decarboxylation of butyric and
isobutyric acid by permanganate ion in moderately concentrated
acidic medium has been studied. The premicellar kinetics has been
rationalised in the light of pseudo-phase model. The positive
cooperativity index (n = 2.09) has been computed. The decarboxy-lation
reactions are acid catalysed and, therefore, various hypotheses
for the mechanism of acid catalysis were tested. Thus, the role of
water molecule as proton abstracting agent is established. On
addition of fluoride ions, a known complexing agent, there is a
decrease in the reaction rate. The effects of variation of ionic
strength and thermodynamic parameters have been computed. The
stoichiometry for the reaction is:
5CH₃CH₂CH₂COOH + 2MnO₄^- + 6H⁺→ 
5CH₃CH₂CH₂OH + 3H₂O + 5CO₂ + 2Mn²⁺
On the basis of the various observations and product characterization
a most plausible mechanism has been envisaged.