Acid hydrolysis
Water adds to the protonated ester carbonyl. Proton transfer allows methanol to leave as the carbonyl reforms, producing the acid and alcohol together.
- Reagents
- Water; dilute acid catalyst
- Conditions
- Heat in aqueous acid; reversible hydrolysis
- Reaction class
- Acid hydrolysis
- Equation
- CH3COOCH3 + H2O <=> CH3COOH + CH3OH
Overview
Water adds to the protonated ester carbonyl. Proton transfer allows methanol to leave as the carbonyl reforms, producing the acid and alcohol together.
Transformation
Methyl acetate → Ethanoic acid
- Equation
- CH3COOCH3 + H2O <=> CH3COOH + CH3OH
- Reactants
- Methyl acetate + Water
- Products
- Ethanoic acid + Methanol
- Reagents
- Water; dilute acid catalyst
- Environment
- Heat in aqueous acid; reversible hydrolysis
- Reaction class
- Acid hydrolysis
- Mechanism
- acid-catalysed ester hydrolysis
- Evidence level
- source-backed molecular example
Scope and limitations
- Scope
- Methyl acetate yields both ethanoic acid and methanol.
- Limitations
- The two product branches describe one reaction. Alkaline hydrolysis would instead produce an ethanoate salt until acid work-up.
Related reactions
- Oxidation: Ethanol → Ethanoic acid
Ethanol is oxidised to ethanoic acid.
- Oxidation: Ethanal → Ethanoic acid
Ethanal is oxidised to ethanoic acid.
- Esterification: Ethanoic acid → Ethyl acetate
Ethanoic acid and ethanol combine reversibly to form ethyl acetate and water.
- Acid hydrolysis: Ethyl acetate → Ethanoic acid
Ethyl acetate and water react reversibly to form ethanoic acid and ethanol.
- Amide hydrolysis: Acetamide → Ethanoic acid
Acid activates the amide carbonyl for water addition. Proton transfer makes nitrogen a better leaving group before C-N cleavage; the acyl fragment becomes ethanoic acid and the nitrogen ends as ammonium.
- Esterification: Methanol → Methyl acetate
Methanol attacks an acid-activated carbonyl; proton transfers and water loss give methyl acetate. The ester oxygen linking to the methyl group comes from the alcohol.
- Acid hydrolysis: Methyl acetate → Methanol
Water adds to the protonated ester carbonyl. Proton transfer allows methanol to leave as the carbonyl reforms, producing the acid and alcohol together.
References
- Organic Chemistry: Chemistry of EstersJohn McMurry · OpenStax Organic Chemistry · 2023
Distinguishes reversible acid-catalysed ester hydrolysis from alkaline saponification, which gives a carboxylate ion until a separate acidification step.