Question

Why endo cyclic double bond is more stable than exo cyclic double bond?

Answer 1

Answer:

Explanation:

The exocyclic product has more substituent groups on the alkene which should make it more stable .

The stability mainly comes from hyperconjugation, which I would expect to be stronger in the isopropyl moiety.

ENDOCYCLIC DOUBLE BOND;

An endocyclic double bond is a double bond inside of a ring system. An exocyclic bond is outside of the ring system. When you have bicyclic and higher order fused ring systems, you have to look at each bond with respect to the rings.

In respect to ring 1, you have an exocyclic and an endocyclic bond while in ring 2 you only have an endocyclic bond.

Answer 2

Due to Resonance

Explanation:

• Endo cyclic double bonds are more stable than the exo cyclic double bonds because endo cyclic bonds are involved in the resonance
• Resonance helps in delocalization of double bonds inside the ring, which lowers the energy of a molecule making it more stable
• The exo cyclic bonds do not experience resonance so endo cyclic bonds are more stable than exo cyclic double bonds
• These endo bonds are termed resonance stabilized bond