1.1: n-BuLi / tetrahydrofuran; hexane / 0.17 h / -10 °C 1.2: 100 percent / tetrahydrofuran; hexane / -10 - 20 °C 2.1: 100 percent / diisobutylaluminium hydride / hexane / 2 h / -78 °C View Scheme