Sigmatropic rearrangements in the synthesis of heterocyclic compounds and their functionalization

Sigmatropic rearrangements are well documented in the carbocyclic as well as heterocyclic chemistry. Various molecules have been obtained from easily accessible starting materials via involvement of sigmatropic rearrangements. This review presented a brief account of the synthesis of some important heterocyclic compounds and their functionalization involving sigmatropic rearrangements, particularly, [3,3]-, [2,3] and [1,5]-ones. The mechanism of some rearrangements has also been discussed.