1.1: 91 percent / Cs2CO3; K2CO3 / dimethylformamide / 10 h / 20 °C 2.1: (Me3Si)2NLi / tetrahydrofuran / 0.33 h / 0 °C 2.2: 90 percent / tetrahydrofuran / 12 h / 20 °C 3.1: 99 percent / sodium tert-butoxide / methanol / 4 h / 20 °C View Scheme