Chapter 24, Problem 24.2P

Interpretation Introduction

Interpretation:

The transition state for the given cycloaddition reaction is to be drawn. Whether the same reaction takes place readily or not is to be explained.

Concept introduction:

The reaction in which same or different species are joined by the cyclic movement of electrons with the formation of a ring is called a cycloaddition reaction. These reactions also proceed through cyclic transition state. The reaction proceeds through an aromatic transition state and occurs readily under normal condition. The reactions proceeding through an antiaromatic transition state do not occur under the normal condition and do not occur readily under normal conditions. Thus, these reactions are called forbidden reactions. Since the Diels-Alder reaction proceeds through an aromatic transition state, it occurs readily under normal condition.