2-Oxoadipic acid, also known as ñ-ketoadipic acid, is an intermediate in the metabolism of lysine and tryptophan. The conjugate base and carboxylate is 2-oxoadipate or ñ-ketoadipate, which is the biochemically relevant form. Glutaric acid is naturally produced by chain extension of ñ-ketoglutarate to 2-oxoadipic acid.