Pericyclic Reaction Types and Features

Pericyclic reactions are organic reactions that happen through a concerted mechanism, which means they proceed in one step without intermediates. Electrons move in a closed loop to form a cyclic transition state. In that transition state, the sigma and pi bonds rearrange to give specific products.

Based on the mechanism, organic reactions can be broadly classified as ionic, radical, and pericyclic. While ionic and radical reactions have well-defined intermediates, pericyclic reactions proceed without any intermediates.

There are three classes of pericyclic reactions: electrocyclic reactions, cycloaddition reactions, and sigmatropic...