1.1: Schwartz's reagent / tetrahydrofuran / 3 h / 20 °C / Darkness 1.2: -78 - -20 °C 1.3: 0.5 h / -78 °C 2.1: diisobutylaluminium hydride / toluene / 3 h / -78 °C 2.2: -50 °C 3.1: 4-(N,N-dimethlyamino)pyridine; diisopropyl-carbodiimide / tetrahydrofuran / 24 h / 20 - 40 °C / Inert atmosphere 4.1: RuCl2(tricyclohexylphosphine)2(benzylidene) / dichloromethane / 18 h / 20 - 40 °C / Inert atmosphere 5.1: tetrabutyl ammonium fluoride; ammonium hydrogen difluoride / tetrahydrofuran / 24 h / 20 - 40 °C 6.1: trimethylaluminum / tetrahydrofuran / 18 h / 20 - 40 °C View Scheme