1.1: Mg / tetrahydrofuran / -78 °C 1.2: 77 percent / tetrahydrofuran / 1 h / -78 °C 2.1: 59 percent / formic acid / CH2Cl2 / 2 h / 20 °C 3.1: 45 percent / tri-n-butylphosphine; carbon tetrachloride / CH2Cl2 / 1 h / Heating 4.1: 80 percent Turnov. / K2CO3 / Pd(OAc)2 / H2O; methanol / 18 h / 20 °C / 760 Torr View Scheme