1: 94 percent / lithium hexamethyldisilazide / tetrahydrofuran / -78 °C 2: 27 percent / Grubbs catalyst 1st generation / benzene / Heating 3: 58 percent / CsF; Pd(PPh3)4 / 1,2-dichloro-ethane / 80 °C 4: 24 percent / Grubbs 2nd generation catalyst / benzene / Heating View Scheme