Hyperconjugation
General Organic Chemistry (GOC) · Chemistry
Study notes
Why is (CH₃)₂C=CH₂ more stable than CH₂=CH₂? Step 1: Alkene stability rises with alkyl substitution. Step 2: (CH₃)₂C=CH₂ has 6 α-hydrogens; their C–H σ bonds donate into the π* system. Step 3: Ethylene has none — no hyperconjugation. Step 4: Heat of hydrogenation confirms: more substituted alkenes release less heat (more stable). Hyperconjugation quantified!