copper(l) iodide; n-butyllithium in tetrahydrofuran T=-60°C; 1 h;

1: 85 percent / triethylamine / tetrahydrofuran / 24 h 2: 70 percent / butyllithium, cuprous iodide / tetrahydrofuran; various solvent(s) / 1 h / -60 °C View Scheme