1: 1.) magnesium, 2.) Li2CuCl4 / 1.) THF, 2.) THF, a) -10 deg C, 1 h, b) 5 deg C, 2 h, c) room temperature, 15 h 2: 74.5 percent / 48percent HBr, conc. H2SO4 / 6 h / Heating 4: 83 percent / a) boron trifluoride, sodium tetrahydroborate, b) water / tetrahydrofuran / a) 3.5 h, b) 10 min 5: 74 percent / pyridinium chlorochromate / CH2Cl2 / 2 h / Ambient temperature View Scheme