A Highly Tunable Stereoselective Dimerization of Methyl Ketone: Efficient Synthesis of E- and Z-1,4-Enediones

A new method for the tunable synthesis of 1,4-enedione directly from aromatic methyl ketone is described. This tandem reaction enables the construction of symmetric and unsymmetric 1,4-enediones with complete E-selectivity. Moreover, the resulting E-1,4-enedione could be transformed into a Z-isomer by irradiation with 23 W of white light.