Diels-Alder Reaction between Butadiene and Cyclopentadiene

The trimers produced by the reaction between butadiene and cyclopentadiene under various conditions were studied by using gas chromatography. The trimers were believed to be produced by the addition reaction of diene with the dimer, which was formed as an intermediate product of the reaction. Under mild conditions the reaction of butadiene with dicyclopentadiene proceeded predominantly. The reaction by combination of other reactants increased gradually with an increase in the reaction temperature in the following order; butadiene-vinylnorbornene, cyclopentadiene-vinylcyclohexene and cyclopentadiene-vinylnorbornene.Moreover, cyclopentadiene-tetrahydroindene and cyclopentadiene-exo-dicyclopentadiene reactions proceeded exclusively under severe conditions.