Chapter 19: Aldehydes and Ketones

Iupac of aldehydes

• Find the longest carbon chain containing the aldehyde group

• Number from the aldehyde carbon.

• Replace the -e ending of the parent alkane with al

• Name and number substituents

• If there is 2 aldehydes use dial.

Iupac of Ketones

• Find the longest carbon chain containing the carbonyl (C=O)

• Number the chain from the part that is closest to the carbonyl. Carbonyl gets the lowest number possible

• Replace the -e ending in the alkane name with one

• Name and number substituents

• If there is 2 ketone groups use, Dione, giving both carbonyl position

Preparations of aldehydes

Preparation of Ketones

Oxidations of aldehydes and ketones

Reactivity of aldehydes and ketones

• Aldehydes are more reactive than ketones

• Ketones are more stable—→ less reactive

• Aldehydes are less stable—→ more reactive

• Straight chain aldehydes are more reactive than aromatic aldehydes

Reactions of aldehydes and ketones

Base-Catalyzed hydration mechanism

Acid Catalyzed hydration mechanism

Nucleophilic addition oh HCN: cyanohydrin formation

Nucleophilic addition oh HCN: cyanohydrin formation mechanism

Nucleophilic addition of an hydride anion

Nucleophilic addition of a grinard reagent mechanism

Nucleophilic addition of amines

Nucleophilic addition of amines mechanism ( Imine formation)

enamine formation mechanism

Nucleophilic addition of hydrazine: The Wolf kishner reaction

Advantages of the wolf-kishners reaction ( reduction)

Nucleophilic addition of alcohols: acetal/ ketal formation

Nucleophilic Addition of Phosphorous ylides ( Wittig reaction)

Conjugate nucleophilic addition to a,B- unsaturated aldehydes and ketones

1,4 addition