How is 8-Sulfanyloctanoic acid (CAS: 74328-61-3) typically synthesized?

8-Sulfanyloctanoic acid can be synthesized through the reaction of octanoic acid with sodium sulfite, followed by acidification to yield the sulfonic acid derivative. This process involves the addition of an excess of sodium sulfite to octanoic acid in the presence of a suitable solvent, such as water or methanol. The mixture is then acidified with a strong acid like sulfuric acid to obtain the final product.