Improved procedures for the Beckmann rearrangement: the reaction of ketoxime carbonates with boron trifluoride etherate

A variety of ketoxime ethyl carbonates—easily prepared from the oximes and ethyl chloroformate—undergo the Beckmann rearrangement upon treatment with 1 equivalent of boron trifluoride etherate, in dichloromethane solution at room temperature in excellent yields (generally 75–99%).