Interrupted Baeyer-Villiger Rearrangement: Building A Stereoelectronic Trap for the Criegee Intermediate

Abstract

The instability of hydroxy peroxyesters, the elusive Criegee intermediates of the Baeyer-Villiger rearrangement, can be alleviated by selective deactivation of the stereoelectronic effects that promote the 1,2-alkyl shift. Stable cyclic Criegee intermediates constrained within a five-membered ring can be prepared by mild reduction of the respective hydroperoxy peroxyesters (β-hydroperoxy-β-peroxylactones) which were formed in high yields in reaction of β-ketoesters with BF₃ ⋅Et₂ O/H₂ O₂ .

Keywords: Baeyer-Villiger reaction; anomeric effects; peroxides; reactive intermediates; stereoelectronics.