dilithium tetrachlorocuprate in tetrahydrofuran T=5°C; 18 h;

1: 42 percent / n-BuLi / tetrahydrofuran; hexane / 1.5 h / -78 °C 2: Et3N / CHCl3 / 14 h / 5 °C 3: 2.54 g / Li2CuCl4 / tetrahydrofuran / 18 h / 5 °C View Scheme

1: 99 percent / K2CO3 / methanol / 17 h / 20 °C 2: 42 percent / n-BuLi / tetrahydrofuran; hexane / 1.5 h / -78 °C 3: Et3N / CHCl3 / 14 h / 5 °C 4: 2.54 g / Li2CuCl4 / tetrahydrofuran / 18 h / 5 °C View Scheme

1: Et3N / CHCl3 / 14 h / 5 °C 2: 2.54 g / Li2CuCl4 / tetrahydrofuran / 18 h / 5 °C View Scheme