Oxidation of Alcohols
The oxidation of alcohols means the chemical process in which the –OH group or the carbon atom attached to it undergoes oxidation, usually by adding oxygen or removing hydrogen. This reaction changes alcohols into other functional groups such as aldehydes, ketones, or carboxylic acids.
Types of Alcohol Oxidation
- Primary Alcohols
- On oxidation, primary alcohols are first converted into aldehydes.
- With further oxidation, they form carboxylic acids.
- Example: Ethanol → Ethanal → Ethanoic acid.
- Secondary Alcohols
- On oxidation, secondary alcohols give ketones.
- Further oxidation (under strong conditions) may break the molecule into smaller acids.
- Example: Isopropanol → Acetone.
- Tertiary Alcohols
- Tertiary alcohols are generally resistant to oxidation because they lack a hydrogen atom on the carbon bonded to –OH.
- Under very strong conditions, they may break down into mixtures of products.
Oxidizing Agents Commonly Used
- Acidified potassium permanganate (KMnO₄).
- Acidified potassium dichromate (K₂Cr₂O₇).
In short:
- Primary alcohols → aldehydes → acids.
- Secondary alcohols → ketones.
- Tertiary alcohols → resistant to oxidation.