1: 0.36 g / NBS; AgNO3 / acetone / 10 h / 25 °C 2: 0.27 g / 1,4-cyclohexadiene; N2 / benzene / 2 h / 180 °C / 15514.9 Torr 3: PdCl2dppf / diethyl ether / Heating 4: NaH; MeOH / tetrahydrofuran / 2 h 5: 64 percent / 1,4-cyclohexadiene / benzene / 160 °C / 12411.9 Torr View Scheme