potassium carbonate in tetrahydrofuran; ethanol T=20°C; 30 h;

1.1: n-BuLi / diethyl ether; hexane / 1 h / -78 °C 1.2: diethyl ether; hexane / -78 - 20 °C 1.3: 48 percent / NH4Cl / diethyl ether; hexane / 5 h / 20 °C 2.1: 75 percent / potassium carbonate / tetrahydrofuran; ethanol / 30 h / 20 °C View Scheme