1.1: 6.8 g / NBS / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: t-BuLi / pentane; tetrahydrofuran / 0.17 h / -78 °C 2.2: 54 percent / pentane; tetrahydrofuran / 0.25 h / -78 °C 3.1: 85 percent / Bu4NF / tetrahydrofuran / 0.17 h / 20 °C View Scheme