1: 80 percent / Mg / Li2CuCl4 / tetrahydrofuran 3: KOH / methanol; hexane; H2O / 2 h / Ambient temperature View Scheme

1: 76 percent / magnesium / tetrahydrofuran / Heating 2: 95 percent / copper(I) iodide / tetrahydrofuran; various solvent(s) / 24 h / -20 - 0 °C View Scheme

magnesium; dilithium tetrachlorocuprate in tetrahydrofuran 10 min, -78 deg C then 2 h, 0 deg C then 15 h, r.t.;