1: 91 percent / NaBH4 / ethanol / 0.5 h / 0 °C 2: 84 percent / imidazole / dimethylformamide / 1 h / 0 °C 3: 92 percent / OsO4; NaIO4 / tetrahydrofuran; H2O 4: 64 percent / tetrabutylammonium fluoride / tetrahydrofuran / 2 h / 20 °C 5: 74 percent / CrO3; H2SO4 / H2O / 0.5 h / 0 °C View Scheme