Oxidation of Some a-Hydroxy Acids by Pyridinium Fluorochromate in Aqueous Acetic Acid Media-A Kinetic and Mechanistic Study

Abstract

Kinetics and mechanism of oxidation of some α-hydroxy acids i.e., glycolic acid, lactic acid or mandelic acid by pyridinium fluorochromate have been studied in aqueous acetic acid medium. The main product of oxidation is oxo acids. The reaction is first order with respect to pyridinium fluorochromate, hydroxy acids and [H + ]. The reaction is acid catalyzed. The oxidation of α-deuterio mandelic acid exhibits a substantial primary kinetic isotope effect (kH/kD = 5.58 at 303 K). The reaction has been studied in different percentage of acetic acidwater mixture. A suitable mechanism has been proposed.

Kinetics and Mechanism of Oxidation of some α - Hydroxy Acids by Tripropylammonium Fluorochromate in Aqueous Acetic Acid Medium

“…The kinetics and mechanism of oxidation of hydroxy acids by various oxidants have been reported [11][12][13][14][15][16][17][18][19] . However, no detailed kinetic study of oxidation of hydroxy acids by TriPAFC, a Cr(VI) reagent has so far been attempted.…”