1.1: SnCl4 / CH2Cl2 / 20.5 h / -10 - 20 °C 2.1: p-TsOH / benzene / 2 h / Heating 2.2: LiAlH4 / diethyl ether / 12 h / 20 °C 3.1: 90 percent / p-TsOH / acetone; H2O / 12 h / 20 °C 4.1: pyridine 5.1: dimethylsulfoxide 6.1: DIBAL / toluene / 2 h / 20 °C View Scheme