1: 98 percent / lithium aluminum hydride / tetrahydrofuran / 1.5 h / Ambient temperature 2: 78 percent / Swern reagent 3: 84 percent / 2.5 M n-butyllithium in hexane / tetrahydrofuran / 0.17 h / -78 °C / 45 min to room temperature 4: 86 percent / aqueous LiOH / acetone / 1.5 h / Heating 5: 1.) 1,1'-carbonyldiimidazole / 1.) CH2Cl2, 0 deg C, 30 min, 2.) CH2Cl2 View Scheme