Showing posts with label Pericyclic reactions-cyclo addition and Diels Alder reactions .. Show all posts
Showing posts with label Pericyclic reactions-cyclo addition and Diels Alder reactions .. Show all posts

Friday, March 22, 2019

Pericyclic reactions-cyclo addition and Diels Alder reactions .


Definition of pericyclic reactions


There is a large body of chemical reactions of olefinic compounds which do not involve ionic or free radical intermediates and which are remarkably insensitive to the presence or absence of solvents and catalysts.

Many of these reactions are characterized by the making and breaking of two or more bonds in a single concerted step through cyclic transition-states where in all first order bonding changes occur.  

Because of their cyclic transition-states, they are known as pericyclic reactions. A pericyclic reaction may occur thermally or photo chemically.