Ruthenium tetroxide (RuO 4) oxidation of N-alkyllactams proceeded regioselectively depending on the size of lactam ring, except for the seven-membered ring. Four-and eight- membered N-methyl-and N-ethyllactams were oxidized at the exocyclic α-carbon adjacent to nitrogen to produce the N-acyllactams and NH-lactams, while five-and six-membered lactams underwent endocyclic oxidation to yield the cyclic imides. Oxidation of seven- ...
