developing character of a double bond in a trisubstituted alkene.
2) The transition state for the reaction leading to 2-methyl-1-butene has the
developing character of a double bond in a disubstituted alkene.
3) Because the transition state leading to 2-methyl-2-butene resembles a more
stable alkene, this transition state is more stable.
Figure 7.6 Reaction (2) leading to the the more stable alkene occurs faster than
reaction (1) leading to the less stable alkene; ∆G‡(2) is less than ∆G‡(1).
i) Because this transition state is more stable (occurs at lower free energy), the
free energy of activation for this reaction is lower and 2-methyl-2-butene is
formed faster.
4) These reactions are known to be under kinetic control.
- Zaitsev rule: an elimination occurs to give the most stable, more highly
substituted alkene
- Russian chemist A. N. Zaitsev (1841-1910).
- Zaitsev’s name is also transliterated as Zaitzev, Saytzeff, or Saytzev.