Conformationally restricted Criegee intermediates: evidence for formation and stereoelectronically controlled fragmentation

The Baeyer–Villiger reaction of 2-(2-oxocyclohexyl)acetic acid occurs via a bicyclic Criegee intermediate, which fragments with stereoelectronic control, as evidenced by product analysis; the reaction of the-but-2-yl ester and of 2-(2-oxocyclopentyl)acetic acid also show evidence of such stereoelectronic control, but less convincingly.