Presentation is loading. Please wait.

Presentation is loading. Please wait.

Dehydration of Alcohols. C - C X Y To make C=C need to eliminate X, Y. Elimination Reactions.

Similar presentations


Presentation on theme: "Dehydration of Alcohols. C - C X Y To make C=C need to eliminate X, Y. Elimination Reactions."— Presentation transcript:

1 Dehydration of Alcohols

2 C - C X Y To make C=C need to eliminate X, Y. Elimination Reactions

3 C - C X Y 1. Concerted (x and y leave same time) 2. X leaves first 3. Y leaves first 3 ways to break 2 bonds

4 Leaving Group

5 Mechanism

6

7 R-XR + + X - Alkene + H + E1 Reaction

8 Elimination 1 bond at a time E1

9 Substitution Elimination Rearrangement SN1SN1 E1 R+R+

10 SN1SN1 E1 SN1

11 C - C X H Strong base Dehydrohalogenation

12 What is the mechanism of dehydrohalogentation? C-D bond stronger than C-H bond. Isotope Effects

13 NaOEt k H /k D = 7 Isotope Effect

14 Isotope effect shows that C-H bond broken in the transition state. Bond Broken in Transition State

15 Change Element I > Br > Cl Element Effect

16 Same Side Opposite Side SYN vs. ANTI Elimination

17

18 E2 Animation

19 Product Starting Material Energy Transition State

20 Elimination 2 Bonds at a time E 2

21 Procedure

22 Put cyclohexanol and sulfuric acid in round bottom flask Fractional Distillation (steam distillation) collect distillate 80-85o Procedure

23 Dry product with K 2 CO 3

24 Distill

25 P T = P A + P B (Steam Distillation) Distil immiscible liquids

26 Potassium Permanganate KMnO 4 Baeyer Unsaturation Tests

27

28 Bromine Addition

29 Bromine and Cyclohexene

30 Br Bromonium Ion

31 Bromonium Ion Intermediate

32 Br - Mechanism

33 Animation


Download ppt "Dehydration of Alcohols. C - C X Y To make C=C need to eliminate X, Y. Elimination Reactions."

Similar presentations


Ads by Google