Chapter 9, Problem 128P

Interpretation Introduction

Interpretation:

A reactant that could be reacts with hexachlorocylopentadiene to gives chlordane through the Diels-Alder reaction has to be given.

Concept Introduction:

Cycloaddition reaction is a concerted addition reaction of two reactants to form a ring; in which two π-bonds are converted to two σ-bonds.

Diels-Alder reaction is a $\left[\text{4+2}\right]\text{ cycloaddition}$ reaction, in which a π-system having four atoms (diene) and a π-system having two atoms (dienophile) are undergoing in cycloaddition reaction and producing a substituted cyclohexene.

The mechanism of the ring formation in the Diels-Alder reaction is drawn by using three arrows representing the shifting of π-bonds in the two π-systems in a clockwise or counter clockwise fashion, so that the ring formation will take place.

Cyclopentadiene can undergo Diels-Alder reaction itself to form a dimer,

Endo-product is the major product in bicyclic-products of Diels-Alder reaction; because the electron-withdrawing substituents of dienophile and the newly forming π-bond of diene are interacted each other.