Intramolecular Pericyclic Reactions of Acetylene Derivatives Leading to Dehydroaromatic and Related Species

Alkynes and cumulenes share the common feature of at least one sp-hybridized carbon atom in the molecule. This leads to the molecules having relatively high energy in the thermodynamic sense, but also having high stability in the kinetic sense. Enediynes, enyne-cumulenes and yne-diynes all undergo pericyclic reactions resulting in cycloaromatization to dehydrobenzenes and related products. In this review, the history, mechanism and synthetic uses of these reactions are discussed.