An Introduction to the Diels-Alder Reaction

The Diels-Alder reaction involves the coupling of a conjugated diene with a dienophile, one that is normally activated by an electron-withdrawing group, to give a substituted cyclohexene ring. During the reaction, two σ bonds are formed at the expense of two π bonds. It is the archetypal pericyclic reaction, and is classed as a cycloaddition. This means it proceeds through a concerted mechanism…