Chapter 16.9, Problem 22ATS

Interpretation Introduction

Interpretation: The product has to be identified and the reason for not forming the other product has to be determined.

Concept Introduction:

There are mainly three types of pericyclic reactions,

1. 1) Electrocyclic reactions.
2. 2) Cycloaddition reactions
3. 3) Sigmatropic reactions

In an electrocyclic reaction “one new sigma- bond is formed or broken.”

$\begin{array}{ccc}\begin{array}{l}\text{Electron}\\ \text{system}\end{array}& \text{Heat}& \text{hυ}\\ \text{4π}& \text{Con}& \text{Dis}\\ \text{6π}& \text{Dis}& \text{Con}\end{array}$

If the two orbitals rotate in same direction, then it is called as con rotation and if it is in opposite direction, then it is called dis rotation.