1: 16 g / NaBH4 / ethanol / 12 h / 20 °C 2: 77 percent / N-bromosuccinimide; PPh3(polystyrene-bound) / CH2Cl2 / 1 h / 20 °C View Scheme

1.1: 16 g / NaBH4 / ethanol / 12 h / 20 °C 2.1: 77 percent / N-bromosuccinimide; PPh3(polystyrene-bound) / CH2Cl2 / 1 h / 20 °C 3.1: NaH / dimethylformamide / 0.5 h / 20 °C 3.2: dimethylformamide / 1 h / 80 °C 4.1: 253 mg / lithium hydroxide monohydrate / tetrahydrofuran / 2 h / 60 °C 5.1: Et3N; bis(oxo-3-oxazolidinyl)phosphoryl chloride / CH2Cl2 / 0.5 h / 20 °C 5.2: 60 percent / CH2Cl2 / 16 h / 20 °C View Scheme