Palladium(II) acetate mediated oxidative cyclization of omega-unsaturated alpha-cyano ketones. A facile methylenecyclopentane annulation process.

A highly efficient methylenecyclopentane annulation process has been developed based on the Pd(II)-mediated oxidative cyclization of omega-unsaturated alpha-cyano ketones, readily accessed via the Michael addition of 3-butenylmagnesium bromide with 2-cyano-2-cycloalkenones.