Synthesis of carboxylic acids

1. Oxidation of primary alcohols with chromic acid or KMnO₄

2. Cleavage of alkenes with vigorous KMnO_4:This gives ketones or carboxylic acids, depending on the specific alkene.

3. Cleavage of alkynes with O₃ or vigorous KMnO₄

4. Carboxylation of Grignards

Reactions of Carboxylic Acids

1. Hydrolysis of acid derivatives

2. Fischer Esterification

Overall: Carboxylic acid + alcohol → ester + water

Step 1: protonation of carbonyl to “activate” it for attack.

Step 2: Alcohol attacks carbonyl carbon of the acid

Step 3: Deprotonation of the oxygen from the alcohol

Step 4: Protonation of one of the oxygens from the acid

Step 5: Loss of water, forming a resonance-stabilized carbocation

Step 6: Deprotonation of carbonyl

3. Hydrolysis of esters: When it’s base-catalyzed, it’s called saponification.

4. Hydrolyzing triglycerides with base, gives carboxylates with long fatty chains.

These chains form micelles. Water-soluble with lipophilic interiors.

5. Direct formation of amides: Acid on strong heating with amine gives amide.

Step 1: Acid Base reaction

On strong heating amide is formed.

6. Polymerization: Dicarboxylic acids with difunctional groups form long chains

7. Reaction with alkyl lithiums: The alkyl lithium first deprotonates the carboxyl group, giving the carboxylate.A second alkyl lithium then adds to the carbonyl, which after protonation, forms the ketone.

8. Reduction of carboxylic acids

1. COOH to 1° alcohol with LiAlH4