Kinetics of oxidation of heterocyclic secondary alcohols by N-chloro-r-2,c-6-diphenyl-t-3 methyl piperidin-4-one (NCP) in perchloric acid medium

Article abstract of DOI:10.1002/kin.550260806

An investigation of the kinetics of oxidation of epimeric piperidin-4-ols, oxan-4-ols, and cyclohexanol by N-chloro-r-2, c-6-diphenyl-t-3-methylpiperidin-4-one (NCP) in aqueous acetic acid in the presence of perchloric acid shows that the reaction is first-order each in substrate and oxidant. Both H₃O⁺ and Cl^- which catalyze the reaction, exhibit a fractional order kinetics. While increase in ionic strength increases the rate slightly, an inverse dependence is observed between rate and solvent polarity. Addition of r-2-c-6-diphenyl-t-3-methylpiperidin-4-one, one of the reaction products, did not influence the rate. Also, no kinetic isotope effect has been observed. A plausible mechanism consistent with these observations is proposed and the relative reactivities of the substrates are explained on conformational grounds.