Grubb's 2nd generation catalyst in toluene 5 h; RefluxInert atmosphere;

1.1: oxalyl dichloride / N,N-dimethyl-formamide; toluene / 2 h / 20 °C 2.1: triethylamine / dichloromethane / 0 - 20 °C 3.1: sodium hydride / tetrahydrofuran / 0 - 20 °C 3.2: -78 - 20 °C 4.1: Grubb's 2nd generation catalyst / toluene / 5 h / Reflux; Inert atmosphere View Scheme

1.1: triethylamine / dichloromethane / 0 - 20 °C 2.1: sodium hydride / tetrahydrofuran / 0 - 20 °C 2.2: -78 - 20 °C 3.1: Grubb's 2nd generation catalyst / toluene / 5 h / Reflux; Inert atmosphere View Scheme