Diels-Alder Reaction

Abstract

In this chapter, we will consider the one reaction of maleic anhydride that has been most investigated in the last half-century. Of historical significance is the formation of a cyclohexene derivative 3 from a conjugated diene (butadiene) 2 and a dienophile (maleic anhydride, MA) 1 as reported by Otto Diels and Kurt Alder in 1928.(1)* This reaction is called the Diels-Alder (DA) reaction, diene synthesis, or the [4 + 2] cycloaddition reaction. The role that MA has played in this reaction along with other dienophiles cannot possibly be covered in a single chapter such as this. The impetus it provided to synthetic organic research, particularly in the fields of steroids, polycyclic aromatics, and alkaloids, by allowing a one-step ring closure, can barely be exemplified in a treatment such as this. The efforts of Diels and Alder were duly recognized by a Nobel Prize for chemistry in 1950.(2)