Chapter 19: Carboxylic Acids
Oxidation of Alkyl Benzenes
(review of Chapter 11)
Reaction type: Oxidation
Summary:
When treated under strong oxidising conditions,
benzylic-H
are oxidised all the way to the carboxylic acid.
Common reagents : Hot, acidic KMnO
4
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.
QUESTION
Why don't 3
o
alkyl aromatic substituents get oxidised ?
ANSWER
©
Dr. Ian Hunt
, Department of Chemistry, University of Calgary
