Nucleophilic addition to carbonyl groups

General reaction

1. Nucleophile attack on carbonyl C and transfer of proton from double bond to O

2. Protonation of -O with acid

3. Nucleophilic addition product

Acid-catalysed general reaction

1. Protonation of =O with acid.

2. Nucleophile attack on carbonyl C and transfer of proton from double bond to OH-

3. Deprotonation of nucleophile on carbonyl C

4. Tetrahedral product and regenerated acid catalyst

Acid-catalysed HYDRATE formation

1. Protonation of =O with acid (H3O+, H+ etc)

2. Nucleophile attack of H2O on carbonyl C and transfer of proton from double bond to OH-

3. Deprotonation of H2O with H2O

4. Hydrate product and regenerated acid catalyst

Base-catalysed HYDRATE formation

1. Nucleophile attack of OH- on carbonyl C and transfer of proton from double bond to O

2. Protonation of O- with H2O to give second OH group

3. Hydrate product with regenerated base catalyst

Acid-catalysed HEMIACETAL formation

1. Protonation of double bond O with acid catalyst to give OH

2. Nucleophile attack on carbonyl C with R’’-OH and transfer of proton from double bond to OH

3. Deprotonation of H from R’’-OH with A- from catalyst to give OR’’

4. Hemiacetal and regener

Acid-catalysed ACETAL formation

1. Protonation of hemiacetal OH group with acid catalyst

2. Dehydration, removal of H2O and transfer of proton from OR’’ to give double bond

3. Nucleophile attack with R’’’-OH on carbonyl C and transfer of proton from double bond to OR’’

4. Deprotonation of R’’’-OH with A- from initial protonation

5. Acetal product and regenerated acid catalyst

Reaction of PRIMARY AMINE for IMINE formation

1. Nucleophile attack of Carbonyl C with R’’-NH2 and transfer of proton from double bond to O

2. Protonation of O- with acid (H3O+) and deprotonation of R’’-NH2 with H2O

3. Protonation of OH with acid (H3O+) to release H2O. Transfer of proton from R’’-NH to make double bond and proton transfer to separate OH-

4. Deprotonation of R’’-NH with H2O

5. Imine product and regenerated acid catalyst

Reduction with METAL HYDRIDES for ALCOHOL formation

1. Nucleophile attack of carbonyl C with NaBH4 or LiAlH4 and transfer of proton from double bond to O

2. Hydrolysis of O-BH3Na+ with H2O to give OH

3. Secondary alcohol product

ALDEHYDE + metal hydride —> PRIMARY ALCOHOL

KETONE + metal hydride —> SECONDARY ALCOHOL

Reaction with GRIGNARD REAGENTS for ALCOHOL formation

1. Nucleophile attack of R’’-MgX on carbonyl C and transfer of proton from double bond to O

2. Protonation of O- with acid (H+)

3. Alcohol product

Aldehyde + Grignard reagent

Give primary alcohol. Other aldehydes from secondary alcohol.

Ketones + Grignard reagent

Gives tertiary alcohol

Carbon dioxide + Grignard reagent

Gives carboxylic acid (R-COOH)