1. Formation of Alkoxide Ions

2. Alcohol - Preparation

3. Alcohol – Preparation – Alkene Hydration
Markovnikov’s Rule
Markovnikov’s Rule
Anti-Markovnikov’s Rule

4. Alcohol – Preparation – Alkene Hydration

5. Alcohol – Preparation – Carbonyl Reduction

6. Alcohol – Preparation – Carbonyl Reduction
Nucleophilic attack
LiAlH4 is much more reactive than NaBH4 but also more dangerous

7. Question
Which one of the isomeric alcohols of formula C5H12O can be prepared by LiAlH4 reduction of a ketone?
A) 1-pentanol
B) 2-methyl-2-butanol
C) 3-methyl-2-butanol
D) 2,2-dimethyl-1-propanol

8. Alcohol – Preparation – Carbonyl Reduction
Catalytic Reduction – Hydrogenation
Give second example of ketone

9. Alcohol preparation – Carboxylic acid and ester reduction

10. Question

11. Grignard Reagents
Similar to hydride reagent

12. Grignard Reagents Reactions

13. Grignard Reagents Reactions
Ester Reaction

14. Alcohol from Epoxide – Reaction with Grignard Reagent or Alkoxide
Reaction with alkoxide:

15. Alcohol – Reactions

16. Alcohol – Reactions – Alkyl halides

17. Alcohol – Reactions – Alkyl halides
An alternative method for the synthesis of 1° and 2° bromoalkanes is reaction of an alcohol with phosphorus tribromide

18. Alcohol – Reactions – Alkyl halides
Step 1: formation of a protonated dibromophosphite converts H2O, a poor leaving group, to a good leaving group Step 2: displacement by bromide ion gives the alkyl bromide

19. Alcohol – Reactions – Alkyl halides
Thionyl chloride is the most widely used reagent for the conversion of 1° and 2° alcohols to alkyl chlorides

20. Alcohol – Reactions – Alkyl halides
Step 1: formation of an alkyl chlorosulfite Step 2: nucleophilic displacement of this leaving group by chloride ion gives the chloroalkane

21. Alcohol – Reactions – Dehydration2 S O 4 C H 3 2 O C H 2 = + O
180°C

22. Alcohol – Reactions – Dehydration
where isomeric alkenes are possible, the alkene having the greater number of substituents on the double bond (the more stable alkene) usually predominates (Zaitsev rule)

23. Alcohol – Reactions – Ester formation
Reaction of carboxylic acid and Alcohol:
Reaction of Acyl chloride and Alcohol:
Acyl adonsine phosphate