ABSTRACT
Rearrangement is a class of organic reactions, where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. Often a substituent moves from one atom to another atom in the same molecule, that is, the mechanism of rearrangement is mainly intramolecular, although intermolecular rearrangements also take place. A rearrangement is not well represented by simple and discrete electron transfers. In pericyclic reactions, explanation by orbital interactions gives a better picture than simple discrete electron transfers. Three key rearrangement reactions are 1,2-rearrangements, pericyclic reactions and olefin metathesis.
