1.1: BuLi / tetrahydrofuran; hexane / 1 h / -78 - -20 °C 1.2: CeCl3 / tetrahydrofuran; hexane / 1 h / -78 °C 1.3: 0.74 g / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: 82 percent / Bu4NF / tetrahydrofuran / 0.5 h / 20 °C View Scheme