Chapter 5: Structure and Preparation of Alkenes. Elimination Reactions

Summary

Alkenes contain the C=C functional group which can be prepared by 1,2-elimination (also known as β-elimination) reactions such as:

• dehydration of alcohols (- H₂O) or
• dehydrohalogenation of alkyl halides (- HX).

Zaitsev's rule indicates that the preferred product is the more highly substituted, and therefore more stable alkene. But the rule is not always obeyed and the anti-Zaitsev (or Hofmann) product can dominate.

Alkenes

• Nomenclature
• Stability
• Structure
• Reactivity

• Dehydration of alcohols
• Dehydrohalogenation of alkyl halides

• Overview
• E1 mechanism
• E2 mechanism
• Selectivity
• Sample questions

© Dr. Ian Hunt, Department of Chemistry