Baeyer-Villiger Oxidation: Migration Preferences
Order of migration of substituents at the carbonyl group
In principle, unsymmetrical ketones can give rise to two ester products depending on which of the substituents is migrating. Similar to the Wagner-Meerwein rearrangement, the following order of migration has been established:
One criterion by which to judge the migratory ability of substituents is their ability to stabilize a partial positive charge. The better the stabilization the higher the migratory aptitude.
The migrating ability is increased by electron-donating and decreased by electron-withdrawing substituents at the migrating group.