The customary laboratory source of 1,3-cyclopentadiene is a compound called “dicyclopentad...

The customary laboratory source of 1,3-cyclopentadiene is a compound called “dicyclopentadiene” (C10H12). Dicyclopentadiene is the Diels-Alder cycloaddition product of two molecules of 1,3-cyclopentadiene. One molecule acts as diene, the other as a dienophile. Heating dicyclopentadiene causes it to undergo a retro Diels-Alder reaction to give 1,3-cyclopentadiene.

What is the structure of dicyclopentadiene?