Methyl 6-chloro-6-oxohexanoate

Its reactive chloro and keto functionalities allow the introduction of sulfur atoms and subsequent cyclization to form the characteristic 1,2‑dithiolane ring of α‑lipoic acid, which is then hydrolyzed and oxidized to produce the final active pharmaceutical ingredient. Methyl 6‑chloro‑6‑oxohexanoate is an important pharmaceutical intermediate in the synthesis of α‑lipoic acid.