1.1: manganese(IV) oxide; sodium carbonate / dichloromethane / 0.5 h / 0 - 25 °C / Inert atmosphere 2.1: sodium hexamethyldisilazane / tetrahydrofuran; hexane / 0.5 h / 25 °C / Inert atmosphere 2.2: 2 h / -78 °C / Inert atmosphere 3.1: Grubb's 2nd generation catalyst / dichloromethane / 6.5 h / 50 °C / Inert atmosphere View Scheme

With  manganese(IV) oxide; sodium carbonate in  dichloromethane T=0 - 25°C; 0.5 h;  Inert atmosphere;