Conformational and steric effects on regioselectivity in the Baeyer–Villiger reaction

Publisher Website
Google Scholar
Abstract
The Baeyer–Villiger oxidation of six β,β,γ-trisubstituted cyclopentanones and cyclohexanones leads to preferential migration of the α-carbon relative to the α′-carbon by a factor of 1.5–4:1. The origin of the preference is suggested to be steric and is ascribed to the greater relief of non-bonded interactions as the α—β bond lengthens in going to the transition state. Thus, in the carbonyl addition intermediate the 1,3-diaxial-like interaction between the hydroxyl and the closest γ-carbon is diminished to a greater extent when the α-carbon migrates relative to the α′-carbon.