Baeyer-Villiger Oxidation

The Baeyer-Villiger oxidation is the reaction of aldehydes or ketones with peroxyacids to form carboxylic acids or esters, respectively. The reaction involves a migration step that is driven by molecular orbital interactions.

1. The nucleophilic terminal oxygen of the peroxyacid attacks the electrophilic carbonyl carbon, forming a tetrahedral intermediate containing a weak O-O bond.
2. The tetrahedral intermediate adopts a conformation where the migrating group is antiperiplanar to the O-O bond, leading to optimal σ to σ* orbital overlap.
3. The more substituted carbon preferentially migrates due to its better ability to stabilize positive charge during the concerted migration and O-O bond cleavage.
4. Migration yields the lactone product and carboxylic acid byproduct.