1. Organic Chemistry 4 th Edition Paula Yurkanis Bruice Chapter 4 Reactions of Alkenes Irene Lee Case Western Reserve University Cleveland, OH ©2004, Prentice Hall

2. Electrophilic Addition of Alkenes

3. Addition of Hydrogen Halides

4. What is the product?

5. a more stable carbocation Carbocation formation is the rate-limiting step

6. Carbocation Stabilities

7. Alkyl groups decrease the concentration of positive charge in the carbocation

8. Delocalization of Electrons

9. Molecular Orbital Diagram in a Hyperconjugation System

10. Hammond postulate: the transition state will be more similar to the species that it is closer to energetically Exergonic reaction: early transition state Endergonic reaction: late transition state

11. I: early transition state II: mid-transition state III: later transition state

12. Reaction Rate and  G ‡ more stable transition state lower  G ‡ faster reaction rate

13. In a regioselective reaction, one constitutional isomer is the major or the only product Markovnikov’s Rule The electrophile adds to the sp 2 carbon that is bonded to the greater number of hydrogens

14. tert-Butyl cation is formed faster and it is more stable

15. Addition of Water to Alkene

16. Hydration of Propene

17. Acid-Catalyzed Addition of Alcohol

18. Rearrangement of Carbocation 1,2-hydride shift a more stable carbocation

19. a more stable carbocation Rearrangement of Carbocation 1,2-methyl shift

20. Carbocation does not always rearrange …

21. Carbocation Rearrangement a more stable carbocation Ring Expansion

22. Addition of Halogens to Alkene

24. Addition of Halogens in the Presence of Water

25. Consider the transition states …

26. Oxymercuration and Mercuration of Alkene

27. Demercuration by Reduction

28. Addition of Borane Hydroboration–Oxidation Anti-Markovnikov’s rule in product formation

29. Anti-Markovnikov addition Markovnikov addition (a pericyclic reaction)

30. Formation of Alkyl Boranes

31. OH Replacement of Boron

32. Anti-Markovnikov Addition of an OH Group

33. Reaction of Carbene with Alkene

34. Synthesis of Bromobutane

35. Generation of Radicals

36. Addition of Radicals to Alkene

37. Relative Stabilities of Alkyl Radicals

38. Calculating the Change in H °

39. Addition of Hydrogen to Alkenes

40. Catalytic Hydrogenation of an Alkene

41. Potential Energies of Pentene Isomers

42. Relative Stabilities of Alkenes

43. Steric Strain in Alkenes

44. Relative Stabilities of Dialkyl- Substituted Alkenes