This document discusses elimination reactions, specifically E1 and E2 reactions. It explains that E1 reactions proceed through a carbocation intermediate and involve a two-step mechanism, while E2 reactions are concerted and involve both the alkyl halide and base in a single step. It also describes factors that influence the reactivity and selectivity of elimination reactions, such as substrate structure, the nature of the leaving group and base, and conformational effects.

4. The E1 Reaction The alkyl halide dissociate, forming a carbocation The base removes a proton The mechanism shows that an E1 reaction is a two-step reaction

7. Energy Diagram for E1

8. Transition States Rate = k [A] See SN1 and E1 Reaction Mechanisms And Radical Chain Reaction

10. Here are four characteristics that the E1 / SN1 mechanisms have in common.

11. Dehydration of Alcohols Acid assisted reactions are always E1

12. The E2 Mechanism

13. Energy Diagram for the E2 Mechanism

14. Transition States Rate = k [A][B] See SN2 and E2 Reaction Mechanisms

18. Here are four characteristics that the E2 / SN2 mechanisms have in common.

19. Effect of the Substrate on E2 Reactivity

20. Bulky leaving groups: Hofmann Elimination This give the anti-Saytzeff product (least substituted product is formed)!

26. The Saytzeff) Rule (Z-rule) According to the Z-rule , the major product in a dehydrohalgenation is the most stable product .