Formation of Alkoxide Ions

Alcohol - Preparation

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

Alcohol – Preparation – Alkene Hydration

Alcohol – Preparation – Carbonyl Reduction

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

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

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

Alcohol preparation – Carboxylic acid and ester reduction

Question

Grignard Reagents Similar to hydride reagent

Grignard Reagents Reactions

Grignard Reagents Reactions Ester Reaction

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

Alcohol – Reactions

Alcohol – Reactions – Alkyl halides

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

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

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

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

Alcohol – Reactions – Dehydration 2 S O 4 C H 3 2 O C H 2 = + O 180°C

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)

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