SolutionsOxidation
1. Aldehydes and ketones versus oxidants
Give the product of the oxidation of: a) 4-hydroxybenzaldehyde with Ag2O; b) cyclopentanone with hot KMnO4; c) cyclohexanone with peroxybenzoic acid.
- 4-Hydroxybenzoic acid; silver oxide oxidizes only the aldehyde.
- Glutaric acid (pentanedioic acid): the C–C bond next to the carbonyl is broken.
- ε-Caprolactone (oxacycloheptan-2-one), by Baeyer-Villiger oxidation.
2. Which group migrates?
Which ester is obtained in the Baeyer-Villiger oxidation of: a) acetophenone; b) cyclohexyl methyl ketone?
- Phenyl acetate: the phenyl group migrates, as it has a higher migratory aptitude than methyl.
- Cyclohexyl acetate: the secondary group (cyclohexyl) migrates, not the methyl.
Order of migratory aptitude: tertiary > secondary ≈ aryl > primary > methyl. The group migrates with retention of configuration.