The oxidation of alcohols was performed successfully in a disperse system with N-oxyl-adsorbed or immobilized silica gel as a disperse phase and aqueous NaOCl as a disperse medium. In the disperse system, the oxidation of sec-alcohols afforded the corresponding ketones, while prim-alcohols were oxidized to aldehydes and/or carboxylic acids depending on their structures and reaction conditions. The N-oxyl-immobilized silica gel was recovered and repeatedly used without a significant change in the product yields. A column-flow system was also investigated for the oxidation of alcohols by use of a newly devised column packed with the N-oxyl-immobilized silica gel.

Efficient and selective oxidation of alcohols is achieved in a disperse system with an N-oxyl--adsorbed or -immobilized silica gel as disperse medium. The N-oxyl-immobilized silica gel can be recovered and used repeatedly for the oxidation. -(TANAKA*, H.; CHOU, J.; MINE, M.; KUROBOSHI, M.; Bull. Chem.