Mechanistic investigations of the N-bromosuccinimide oxidation of trimethylsilyl ethers (preceding paper) catalyzed by 2,2′-azobisisobutyronitrile are described. Based on the proposed mechanism, a highly efficient and versatile preparation of mixed esters from aliphatic and aromatic aldehydes and aliphatic trimethylsilyl ethers has been discovered. Aromatic aldehydes require the presence of a catalytic amount of trimethylsilyl triflate to give the mixed esters directly.