1: dimethyl sulfoxide, sodium hydride 2: LiAlH4 / tetrahydrofuran / 2 h / cooling 3: 96 percent / HCl, SnCl2 4: 84 percent / BBr3 / benzene / 0.75 h / Heating; deoxygenated solvents View Scheme

1: dimethyl sulfoxide, sodium hydride 2: LiAlH4 / tetrahydrofuran / 2 h / cooling 3: 96 percent / HCl, SnCl2 4: 84 percent / BBr3 / benzene / 0.75 h / Heating; deoxygenated solvents 5: 85 percent / pyridine / Ambient temperature View Scheme