1.1: KH / tetrahydrofuran / 0.67 h 1.2: 77 percent / C2Cl6 / tetrahydrofuran / 3 h / 20 °C 2.1: KH / tetrahydrofuran / 0.5 h / 0 °C 2.2: t-BuLi / tetrahydrofuran / 0.33 h / -78 °C 2.3: 74 percent / aq. NaOH / tetrahydrofuran / 0.33 h / -78 - 0 °C View Scheme

1: With potassium hydride in tetrahydrofuran 0.666667 h; 2: With 1,2,2-trichloro-1,1,2-trichloro-ethane in tetrahydrofuran T=20°C; 3 h;