EFFICIENT AND HIGHLY SELECTIVE OXIDATION OF PRIMARY ALCOHOLS TO ALDEHYDES BY N-CHLOROSUCCINIMIDE MEDIATED BY OXOAMMONIUM SALTS

2,2,6,6-Tetramethyl-1-piperidinyloxy catalyzes efficient oxidation of primary alcohols to aldehydes by N-chlorosuccinimide, in a biphasic di chloromethane-aqueous pH 8.6 buffer system in the presence of tetrabut ylammonium chloride. Aliphatic, benzylic, and allylic alcohols are rea dily oxidized with no overoxidation to carboxylic acids. Secondary alc ohols are oxidized to ketones with a much lower efficiency. Very high chemoselectivities are observed when primary alcohols are oxidized in the presence of secondary ones. Primary-secondary diols are selectivel y transformed into hydroxy aldehydes, with, in some cases, no detectab le formation of the isomeric keto alcohols.