An improved protocol for aerobic oxidation of acetals to esters catalyzed by N-hydroxy phthalimide (NHPI) and lipophilic Co(II) complexes

A variety of both open-chain and cyclic acetals are efficiently oxidized to their esters and diol mono esters, respectively, using molecular oxygen in the presence of N-hydroxy phthalimide (NHPI) combined with Co(OCOC5H11)2 at room temperature.