1.1: 86 percent / ammonia (g) / CH2Cl2 / 18 h / -78 - 20 °C 2.1: 95 percent / NEt3 / CH2Cl2 / 4 h / -78 - 20 °C 3.1: nBuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 3.2: 89 percent / tetrahydrofuran; hexane / 16 h / -78 °C 4.1: NEt3; iodine / methanol / 0.33 h / 20 °C View Scheme