Carboxylic acid when reacted with lead tetraacetate and Lithium halide, -COOH group of a carboxylic acid get replaced by halogen atom to form an alkyl halide. This process is called Kochi decarboxylation. Kochi decarboxylation is useful in decreasing the carbon chain in an organic reaction.
- The lone pair of oxygen of -Oh group is donated to the lead atom of lead tetraacetate to form an ester.
- LiCl release Chloride ion, which attack the ester to form an oxychloride compound.
- Rearrangement occur to produce a carbocation. Which attack the Chlorine of another oxychloride molecule to form alkyl halide.