An Investigation of the Reactivity of MCPBA and α-Bromoalkenes under ­Traditional or Microwave-Assisted Conditions: Selective Formation of ­Epoxides or Allylic Bromides

Abstract

The reaction of a-bromo-b,g-unsaturated lactams and esters with m-chloroperbenzoic acid has been studied to find experimental conditions that could afford exclusively epoxide formation or bromide 1,3-shift. The results show a strong dependence of reactivity on the dilution and on the amount of peracid used, suggesting a radical mechanism for the bromine rearrangement. This last reaction is also strongly favored by microwave-assisted conditions.