Organic-Solvent-Free Phase-Transfer Oxidation of Alcohols Using Hydrogen Peroxide

Organic-solvent-free oxidations of alcohols using aqueous hydrogen peroxide in the presence of sodium tungstate and phase-transfer catalysts provide a general, safe, simple, and cost-effective means to prepare ketones. Six representative alcohols, 1-phenylethanol, 1-phenylpropanol, benzhydrol, 4-methylbenzhydrol, cis,trans -4- tert -butylcyclohexanol, and benzyl alcohol are oxidized to the corresponding aldehyde or ketone over 1-3 hours in 81-99% yields. Purities are very high, with only small to trace amounts of starting alcohol remaining. Experiments can be readily designed for one or two 3-hour laboratory periods, integrating the various techniques of extraction, drying, filtration, column chromatography, gas chromatography, NMR and IR spectroscopy, and reaction kinetics.