Definition of pericyclic reaction and its types

Definition of pericyclic reaction ?

A pericyclic reaction is one involving a concerted bond reorganization in which the essential bonding changes occur within a cyclic array of the participating atomic centre.

Example of pericyclic reaction

An example of this type of reaction between furan and furan 2, 5-dione which occur on heating to form a product are as follows,

Types of pericyclic reaction 

There are five types of pericyclic reaction.

1. Cyclo -addition reactions. 2. Electro cyclic reaction 3.Sigmatropic rearrangements 

4. Chelotropic or chele tropic reaction  and 5.The ene  or Alder- ene reaction.

What is Chelotropic or cheletropic reaction ?

Chelotropic reactions are also known as chelotropic reactions, are a type of pericyclic reaction. 

A pericyclic reaction is one that involves a transition state with a cyclic array of atoms and an associated cyclic array of interacting orbitals. A reorganization of σ and π bonds occurs in this cyclic array.

Specifically, chelotropic reactions are a sub class of cyclo additions.

An example of chelotropic reaction between butadiene and sulfurdioxide are as follows,

What  is ene  or  Alder-ene  reaction ?

The ene reaction is also known as Alder-ene reaction, is one type pericyclic reaction .
This reaction occurs between an alkene with an allylic hydrogen (ene) and a compound containing a multiple bond (enophile), in order to form a new σ-bond with migration of the ene double bond and1, 5 hydrogen shift. 

An example of this type of reaction is as follows,

Practice problems:

What is Pericyclic reaction .Give example ?

What is ene or Alder-ene reaction ?

What is chelotropic or cheletropic reaction ?

What is Cyclo additions reaction, give example ?

Clic here: Cyclo addition reaction details.