A Selective and Efficient Method for Alcohol Oxidations Mediated by N-Oxoammonium Salts in Combination with Sodium Bromite

Inokuchi, T.; Matsumoto, S.; Nishiyama, T.; Torii, S. J. Org. Chem. 1990, 55, 462

The oxidation of primary and secondary alcohols leading to aldehydes, carboxylic acids, and ketones has been carried out in a N-oxoammonium salts-NaBrO₂ system. Sodium bromite as a stoichiometric oxidizing reagent activates N-oxyl compounds (recycling catalysts) to their N-oxoammonium salts in a weakly basic medium, which oxidize primary hydroxyl groups preferentially rather than secondary ones to the corresponding aldehydes. Calcium hypochlorite is used as an alternative terminal oxidant in the same media. The procedure, applicable to the selective formation of g-and d-lactones, b-hydroxy aldehydes, and 2-acetoxy ketones, is advantageous in terms of reagent cost, safety, and ease of operation.