The preference for anti over Gauche migration in the Baeyer-Villiger reaction.
Explanations for stereoselectivity in the Baeyer-Villiger reaction have relied on the assumption that the antiperiplanar (app) group migrates. However, the magnitude of the preference for app-migration over gauche migration is unknown. To investigate this, the energy differences between the two were estimated from ab initio calculations. App-migration was found to be the preferred pathway since no transition structure could be located for gauche migration. Barriers for gauche migration were estimated by performing constrained optimizations. App-migration was found to be strongly favored with a barrier that is at least 3.8 kcal/mol and as much as 58.0 kcal/mol lower in energy than the gauche migration barrier.
Snowden
Michelle
M
Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Boulevard, Norfolk, Virginia 20529, USA.
Bermudez
Amy
A
Kelly
David R
DR
Radkiewicz-Poutsma
Jennifer L
JL
D003500:Cyclization; D007659:Ketones / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D007659:Ketones