Chapter 8: Q12P (page 318)
Name the following dienes and rank them from most stable to least stable. (Hint: Alkyl groups stabilize dienes in the same way they stabilize alkenes; Section 5.9.)
Short Answer
The smaller the heat of hydrogenation (the positive value of heat of hydrogenation) the more stable the compound. Therefore, the relative stabilities of dienes are:
Conjugated dieneห isolated dieneห cumulated diene