Chapter  19: Carboxylic Acids

Oxidation of Alkyl Benzenes
(review of Chapter 11)

Summary:

• When treated under strong oxidising conditions, benzylic-H are oxidised all the way to the carboxylic acid.
• Common reagents : Hot, acidic KMnO₄
• The alkyl substituent can be methyl-, 1^o or 2^o alkyl.
• 3^o alkyl are not oxidised because they lack a benzylic-H.
• Simple alkane C-H can not be oxidised in this manner.
• This, therefore gives a potential route to aromatic carboxylic acids.