Polyphosphoric Acid in Organic Synthesis

Polyphosphoric acid (PPA), a powerful dehydrating agent, has been widely used to perform several important organic reactions and thus has played an important role in the synthesis of organic compounds and natural products. The present micro review describes briefly the use of PPA (i) in the cyclization of acids on the aromatic ring (ii) in acetylation and isopropylation on the aromatic ring, (iii)hydrolysis of esters, (iv) cleavage of epoxides and (v) synthesis of heterocyclic compounds.