Reaction Summary
Reagents
- Concentrated acidified
(or )
Conditions
- Hot, heat under reflux (harsh)
Catalyst
- None
Chemical Equation
Equation
By-Products
- None in the [O] equation
Observations
Observations
- Purple solution turns colourless
⚠️ 9701 Exam Notes / Pitfalls
Warning
- Not a standard single-step 9701 reaction — only seen in ‘unfamiliar reaction’ deduction questions. Ketones are normally resistant to oxidation.
- Under harsh conditions a cyclic ketone ring is cleaved next to C=O, giving a dicarboxylic acid with the same number of C atoms (e.g. cyclohexanone ➔ hexanedioic acid).
- For a hydroxydicarboxylic acid, the starting ketone must already carry an OH on a carbon that stays
(e.g. 3-hydroxycyclohexanone above). Cleavage on the other side of C=O gives the isomer 3-hydroxyhexanedioic acid. - A secondary OH would itself oxidise under these conditions in reality — accept the deduction logic, not the practicality.