Oxidation reactions of organic substances must be catalyzed by an oxidizing agent.
They are symbolized by O and may be potassium permanganate (KMnoO4), potassium dichromate (K2Cr2O7) or osmium tetraoxide (OsO4).
The most important oxidation reactions are as follows:
- energetic oxidation of alkenes
- oxidation of primary alcohol
- secondary alcohol oxidation
This oxidation occurs in the alkenes in contact with an oxidizing agent in concentrated aqueous acid solution (usually in sulfuric acid).
In this reaction we can obtain various products depending on the type of double bond position. Watch:
- primary carbon produces carbon dioxide and water
- secondary carbon produces carboxylic acid
- tertiary carbon produces ketone
This reaction serves as an alkene unsaturation test, ie to identify what type of alkene one has. Follow the example:
Here's another example involving tertiary carbons:
Primary alcohols oxidize with energy oxidants such as potassium permanganate and potassium dichromate in sulfuric media.
The product of this oxidation is aldehyde. With more oxidizing agent we get a carboxylic acid.
This reaction explains why wine tastes like vinegar when we leave it too long in contact with air (oxygen). The alcohol oxidizes to vinegar, which is a carboxylic acid.
Secondary alcohols are ketones. Example:
Note: There is no tertiary alcohol oxidation.