Mechanisms for the oxidation of para-substituted benzyl alcohols and benzyl ethers by permanganate

Article abstract of DOI:10.1016/S0040-4039(97)10788-2

Permanganate, solubilized in methyl]ene chloride with the aid of a phase transfer agent, oxidizes benzyl alcohol to benzaldehyde and benzyl ethers to benzoate esters. Although the rate of oxidation of the ether is about an order of magnitude slower than alcohol oxidation, both respond in an identical way to the unique effects caused by introduction of substituents into the ring. In addition, primary kinetic isotope effects are observed for both reactions. Because of these similarities, it is proposed that benzyl alcohols and benzyl ethers are oxidized by similar mechanisms, the difference in rate being ascribed to steric effects.