Ruthenium tetroxide oxidation of N, C-protected derivatives of L-2, 4-diaminobutyric acid, L-ornithine and L-lysine was carried out under two-phase conditions and the corresponding imides, formed through the oxidation of the methylene adjacent to the ω-amino group, were obtained in good yields. Removal of the protecting groups from the products gave L-asparagine, L-glutamine and L-2-aminoadipic acid 6-amide, respectively. Thus, the first chemical conversion of L-α, ω-diamino acids into the corresponding L-ω-carbamoyl-α-amino acids without racemization has been established. L-2-Aminoadipic acid 6-amide was further converted to L-2-aminoadipic acid by acid hydrolysis. This represents a convenient method for the synthesis of L-2-aminoadipic acid starting from L-lysine.