Topic 7Dienes and Alkynes

Dienes and polyenes contain two or more C=C double bonds, and alkynes a C≡C triple bond. When the double bonds are conjugated, the system behaves as a unit and undergoes its own reactions, such as conjugate addition and the Diels-Alder cycloaddition; alkynes, more unsaturated, can add two molecules of reagent and, when terminal, have an acidic hydrogen.