Aldehydes and Ketones: Oxidation and Reduction Reactions

Study Notes

Aldehydes and Ketones:

Oxidation Reactions:
- Aldehydes are easily oxidized to carboxylic acids using oxidizing agents like potassium permanganate (KMnO4) or chromic acid (H2CrO4).
- Ketones are resistant to oxidation due to the absence of a hydrogen atom attached to the carbonyl carbon.
Reduction Reactions:
- Aldehydes and ketones can be reduced to alcohols using reducing agents like hydrogen gas (H2) in the presence of a catalyst.
Addition Reactions:
- Aldehydes and ketones undergo addition reactions with nucleophiles like water, alcohols, and amines to form acetals, hemiacetals, and imines, respectively.
Aldol Reaction:
- Aldehydes and ketones can undergo an aldol reaction, a type of condensation reaction, to form β-hydroxyaldehydes or β-hydroxyketones.

Carboxylic Acids:

Decarboxylation Reaction:
- Carboxylic acids can undergo decarboxylation, a type of elimination reaction, to form carbon dioxide and an alkane.
Esterification Reaction:
- Carboxylic acids react with alcohols to form esters and water, catalyzed by acid or base.
Hydrolysis Reaction:
- Carboxylic acids can undergo hydrolysis, a type of nucleophilic substitution reaction, to form salts and water.

Aldehydes and Ketones:

Polarity:
- Aldehydes and ketones are polar molecules due to the presence of the carbonyl group.
Boiling Point:
- The boiling points of aldehydes and ketones increase with increasing molecular weight.
Solubility:
- Aldehydes and ketones are generally soluble in organic solvents like ethanol and ether.
Reactivity:
- Aldehydes are generally more reactive than ketones due to the presence of a hydrogen atom attached to the carbonyl carbon.

Carboxylic Acids:

Acidity:
- Carboxylic acids are weak acids, donating a proton (H+) in aqueous solutions.
Polarity:
- Carboxylic acids are polar molecules due to the presence of the carboxyl group.
Boiling Point:
- The boiling points of carboxylic acids increase with increasing molecular weight.
Solubility:
- Carboxylic acids are generally soluble in water and organic solvents like ethanol and ether.

Aldehydes are easily oxidized to carboxylic acids using oxidizing agents like potassium permanganate (KMnO4) or chromic acid (H2CrO4).
Ketones are resistant to oxidation due to the absence of a hydrogen atom attached to the carbonyl carbon.
Aldehydes and ketones can be reduced to alcohols using reducing agents like hydrogen gas (H2) in the presence of a catalyst.
Aldehydes and ketones undergo addition reactions with nucleophiles like water, alcohols, and amines to form acetals, hemiacetals, and imines, respectively.
Aldehydes and ketones can undergo an aldol reaction, a type of condensation reaction, to form β-hydroxyaldehydes or β-hydroxyketones.

Carboxylic acids can undergo decarboxylation, a type of elimination reaction, to form carbon dioxide and an alkane.
Carboxylic acids react with alcohols to form esters and water, catalyzed by acid or base.
Carboxylic acids can undergo hydrolysis, a type of nucleophilic substitution reaction, to form salts and water.

Aldehydes and ketones are polar molecules due to the presence of the carbonyl group.
The boiling points of aldehydes and ketones increase with increasing molecular weight.
Aldehydes and ketones are generally soluble in organic solvents like ethanol and ether.
Aldehydes are generally more reactive than ketones due to the presence of a hydrogen atom attached to the carbonyl carbon.

Carboxylic acids are weak acids, donating a proton (H+) in aqueous solutions.
Carboxylic acids are polar molecules due to the presence of the carboxyl group.
The boiling points of carboxylic acids increase with increasing molecular weight.
Carboxylic acids are generally soluble in water and organic solvents like ethanol and ether.