diels-alder+reactions

The **Diels–Alder reaction** is an [|organic chemical reaction] (specifically, a [|cycloaddition] ) between a conjugated [|diene] and a substituted [|alkene], commonly termed the dienophile, to form a substituted [|cyclohexene] system. The reaction can proceed even if some of the atoms in the newly formed ring are not [|carbon]. Some of the Diels–Alder reactions are reversible; the decomposition reaction of the cyclic system is then called the **retro-Diels–Alder**. For example, retro-Diels–Alder compounds are commonly observed when a Diels–Alder product is analyzed via [|mass spectrometry]. [|Otto Paul Hermann Diels] and [|Kurt Alder] first documented the novel reaction in 1928 for which they were awarded the [|Nobel Prize in Chemistry] in 1950 for their work on the eponymous reaction. The Diels–Alder reaction is generally considered one of the more useful reactions in organic chemistry since it requires very little energy to create a [|cyclohexene] ring, which is useful in many other organic reactions.