The present invention relates to the field of organic synthesis and more precisely to a process for the synthesis of an unsaturated aldehyde or ketone by oxidation of the corresponding alcohol. The oxidation is performed by a hypochlorite salt and a catalytic amount of a N-(2,2,6,6-tetraalkyl-4-piperidinyl-N-oxyl)-2-amino-1,3,5-triazine compound, preferably a N-oxyl derivative of one of the polymers known under the trademark Chimassorb 944 or 2020.