# Action of hot alkaline KMnO4 on tert butyl benzene

Side chain oxidation of aryl alkanes takes place if there is at least one alpha hydrogen present by all accounts I presumed that there would be no reaction. However the answer given was trimethyl acetic acid. Is the answer key wrong?

• chemistry.stackexchange.com/a/86/51553 Jul 1 '18 at 18:01
• Permanganate oxidises double bonds, even those in aromatic systems if you use forcing conditions. Jul 2 '18 at 6:17
• My teacher has taught me same rxn. but acc. to him it happens only in acidic conditions not in basic medium Mar 10 '20 at 14:11

$$\large{•}$$ Chromium Oxidations in Organic Chemistry; By G. Cainelli, G. Cardillo
For reaction with $$\ce{KMnO4}$$, the given compound must have a carbon atom attached directly to the ring and that carbon atom must have at least one hydrogen atom. But in case of tert-butylbenzene this condition isn't followed and hence is a special case. The final product obtained on reaction of tert-butylbenzene with $$\ce{KMnO4}$$ is Pivalic acid $$\ce{(CH3)3CCOOH}$$ (Common name: Dimethylpropanoic acid).