1: 89 percent / 1.) boron trifluoride ether complex 2.)sodium tetrahydroborate / tetrahydrofuran / 1 h / 20 °C / nitrogen atmosphere 2: 1.) 40percent HBr 2.) benzoyl chloride / 1.) glac.AcOH, 8 h, 20 degC 2.) DMF, 24 h, 20 degC 3: 90 percent / HBr / diethyl ether / 0.17 h 4: 88 percent / HBr / methanol / 0.17 h 5: 0.044 g / bromine, iodine, triethylamine / various solvent(s) / 0.17 h / Heating 6: 0.031 g / pyridine / Heating; nitrogen atmosphere View Scheme