Controlled oxidation
Oxidation removes hydrogen from the O-H bond and the OH-bearing carbon to form C=O. Separating butanal as it forms limits its further oxidation.
- Reagents
- Acidified K2Cr2O7
- Conditions
- Gentle oxidation with prompt removal of the aldehyde
- Reaction class
- Controlled oxidation
- Equation
- CH3CH2CH2CH2OH + [O] -> CH3CH2CH2CHO + H2O
Overview
Oxidation removes hydrogen from the O-H bond and the OH-bearing carbon to form C=O. Separating butanal as it forms limits its further oxidation.
Transformation
- Equation
- CH3CH2CH2CH2OH + [O] -> CH3CH2CH2CHO + H2O
- Reagents
- Acidified K2Cr2O7
- Environment
- Gentle oxidation with prompt removal of the aldehyde
- Reaction class
- Controlled oxidation
- Mechanism
- primary-alcohol oxidation
- Evidence level
- source-backed molecular example
Scope and limitations
- Scope
- Primary alcohol with a four-carbon chain.
- Limitations
- Continued reflux with excess aqueous oxidant produces butanoic acid.
Related reactions
- Carbonyl reduction: Butanal → Butan-1-ol
Hydride adds to the aldehyde carbon and the carbonyl oxygen becomes an alkoxide. Protonation completes the return to butan-1-ol.
- Aldehyde oxidation: Butanal → Butanoic acid
The hydrated aldehyde is oxidised to a carboxyl group. All four starting carbon atoms remain together in butanoic acid.
- Esterification: Butan-1-ol → Butyl acetate
The alcohol oxygen attacks an activated ethanoic-acid carbonyl. The four-carbon chain remains on oxygen while the two-carbon acetate fragment supplies the carbonyl.
- Acid hydrolysis: Butyl acetate → Butan-1-ol
Hydrolysis breaks the acyl-to-oxygen connection after water addition and proton transfer. The original butyl group stays attached to oxygen and leaves as butan-1-ol.
References
- Pearson Edexcel International Advanced Level Chemistry Scheme of WorkPearson Education Limited · Pearson qualifications · 2018
Official Pearson teaching guidance specifying chloroalkane-relevant conditions: aqueous alkali, ethanolic potassium hydroxide, alcoholic ammonia, alcoholic potassium cyanide, and PCl5 alcohol chlorination.