1.1: 100 percent / oxalyl chloride / CH2Cl2 / 15 h / 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: tetrahydrofuran; hexane / 1 h / -78 °C 3.1: 2.94 mg / NaBH4 / ethanol / -78 - 20 °C 4.1: 93 percent / LiAlH4 / tetrahydrofuran / 0.5 h / 0 °C View Scheme