1. Case Western Reserve University
Chapter 4
Reactions of
Alkenes
Organic Chemistry
4th Edition
Paula Yurkanis Bruice
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. Carbocation formation is the rate-limiting step
a more stable
carbocation

6. Carbocation Stabilities

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

8. Delocalization of Electrons

9. Markovnikov’s Rule
The electrophile adds to the sp2 carbon that is bonded to the greater number of hydrogens
In a regioselective reaction, one constitutional isomer is the
major or the only product

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

11. Addition of Water to Alkene

12. Hydration of Propene

13. Acid-Catalyzed Addition of Alcohol

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

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

16. Carbocation does not always rearrange …

17. Addition of Halogens to Alkene

19. in the Presence of Water
Addition of Halogens
in the Presence of Water

20. Consider the transition states …

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

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

23. Formation of Alkyl Boranes

24. OH Replacement of Boron

25. Anti-Markovnikov Addition
of an OH Group

26. Synthesis of Bromobutane

27. Calculating the Change in H°

28. Addition of Hydrogen to Alkenes

29. Catalytic Hydrogenation of an Alkene

30. Potential Energies of Pentene Isomers

31. Relative Stabilities of Alkenes

32. Steric Strain in Alkenes

33. Relative Stabilities of Dialkyl-Substituted Alkenes