The recently reported efficient conversion of cyclic ketones to lactones by Oxone in neutral buffered water is extended to heterocyclic ketones, namely, cyclic N-Boc azaketones and oxoethers with the aim of obtaining N-protected azalactones and their analogues with oxygen in place of nitrogen. N-Boc-4-piperidinone and all the cyclic oxoethers were successfully oxidized to lactones, while the azacyclic ketones with nitrogen α-positioned to carbonyl were univocally transformed into N-Boc-ω-amino acids and N-Boc-N-formyl-ω-amino acids operating in alkaline water and DMF, respectively.