Diels-Alder Reaction: s-cis E-1,3-pentadiene

The s-cis conformation about the C2-C3 bond is a local minimum on the potential energy surface. This structure is about 2.7 kcal/mol less stable than s-trans E-1,3-pentadiene. This diene conformation is the reactive conformation in Diels-Alder reactions.


Figure. The MP2(full)/6-31G* optimized structure of s-cis E-1,3-pentadiene.