1.1: 6.4 g / NBS / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: t-BuLi / pentane; tetrahydrofuran / 0.17 h / -78 °C 2.2: pentane; tetrahydrofuran / 0.25 h / -78 °C 3.1: 190 mg / Bu4NF / tetrahydrofuran / 0.17 h / 20 °C View Scheme

1: 89 percent / NBS / tetrahydrofuran / 3 h / -78 °C 2: 79 percent / t-BuLi / tetrahydrofuran; pentane / 2 h / -78 °C 3: 97 percent / Me2NH / tetrahydrofuran / 3 h / 20 °C View Scheme

1.1: 6.4 g / NBS / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: t-BuLi / pentane; tetrahydrofuran / 0.17 h / -78 °C 2.2: pentane; tetrahydrofuran / 0.25 h / -78 °C 2.3: Bu4NF / tetrahydrofuran / 0.17 h / 20 °C View Scheme