Chapter 11.13, Problem 21P

Interpretation Introduction

Interpretation:

The structure of the productformed by intramolecular Diels–-Alder reaction of the given compound at room temperature is to be drawn.

Concept introduction:

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The conjugate addition of alkene to diene is the Diels–-Alder reaction. Diels–-Alder reaction is a cycloaddition occurring through the formation of six-membered cyclic transition state.This is a concerted mechanism in which the single step reaction with no intermediate formation takes place.

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Dienophile is the alkene that adds to diene.Diene is an electron-rich system attacksan electron deficient dienophile.The diene and dienophile, when residing in a single molecule, the intramolecular Diels–-Alder reaction is possible.

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In order to form the cyclic transition state in Diels–-Alder reaction, the conjugated diene must be able to adopt $\text{s-cis}$ conformation.

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The $\text{s-cis}$ conformation is the conformation of a single bond separated by two double bonds which are in the same plane and pointing in the same direction.The structure is shown below: