1: 75 percent / 10percent HCl / 1,2-dimethoxy-ethane / 6 h / 65 °C 2: 47 percent / triphenylphosphine, diethyl azodicarboxylate / benzene / 65 h / 25 °C 3: Raney nickel / ethanol / 80 °C 4: LiAlH4 / tetrahydrofuran View Scheme