9: Elimination Reactions
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- 9.1: Reactions of Alkyl Halides- Substitution and Elimination
- The two major reaction pathways for alkyl halides (substitution and elimination) are introduced.
- 9.2: Characteristics of the E2 Reaction
- E2, bimolecular elimination, was proposed in the 1920s by British chemist Christopher Kelk Ingold. In E2 reactions, a beta-hydrogen and the leaving group are eliminated from an alkyl halide in reaction with a strong base to form an alkene.
- 9.3: Zaitsev's Rule
- Zaitsev's Rule can be used to predict the regiochemistry of elimination reactions. Regiochemistry describes the orientation of reactions about carbon-carbon double bonds (C=C).
- 9.4: Characteristics of the E1 Reaction
- The unimolecular E1 mechanism is a first order elimination reaction in which carbocation formation and stability are the primary factors for determining reaction pathway(s) and product(s).
- 9.5: E2 Regiochemistry and Cyclohexane Conformations
- Cyclohexyl halides provides the perfect opportunity to learn and understand the regiochemistry of the E2 reaction and why Zaitsev's Rule does not always apply. The anti-coplanar orientation of the E2 mechanism can also be see with certain carbon chain diastereomers.
- 9.6: The E2 Reaction and the Deuterium Isotope Effect
- The bimolecular transition state of the E2 reaction illustrates the effects of bond strength on reaction rates when studying the kinetic isotope effect of deuterium.
- 9.7: Comparison of E1 and E2 Reactions
- The strength of the base is the primary consideration when distinguishing between the E1 and E2 pathways. The reaction solvent is a secondary consideration.
- 9.8: Comparing Substitution and Elimination Reactions
- Chemical reactivity patterns can help us determine the most favorable pathway among the closely related SN1, SN2, E1, and E2 mechanisms.
- 9.9: Biological Elimination Reactions
- A few examples of biochemical E1 and E2 mechanisms are introduced.
- 9.10: Additional Exercises
- This section has additional exercises for the key learning objectives of this chapter.
- 9.11: Solutions to Additional Exercises
- This section has the solutions to the additional exercises from the previous section.