1: 92 percent / NaBH4 / methanol / 0.5 h / Ambient temperature 2: 86 percent / BF3*Et2O / 4 h / -25 - -18 °C 3: 100 percent / n-Bu4NF*3H2O / tetrahydrofuran / 1.5 h / -21 - -17 °C 4: 846 mg / CrO3, pyridine / CH2Cl2 / 0.5 h / Ambient temperature 5: NH3 / methanol / 20 h / Ambient temperature 6: 82 percent / TFA / H2O / 5 h / Ambient temperature View Scheme

1: 92 percent / NaBH4 / methanol / 0.5 h / Ambient temperature 2: 86 percent / BF3*Et2O / 4 h / -25 - -18 °C 3: 100 percent / n-Bu4NF*3H2O / tetrahydrofuran / 1.5 h / -21 - -17 °C 4: 846 mg / CrO3, pyridine / CH2Cl2 / 0.5 h / Ambient temperature 5: NH3 / methanol / 20 h / Ambient temperature View Scheme

1: 92 percent / NaBH4 / methanol / 0.5 h / Ambient temperature 2: 86 percent / BF3*Et2O / 4 h / -25 - -18 °C 3: 100 percent / n-Bu4NF*3H2O / tetrahydrofuran / 1.5 h / -21 - -17 °C View Scheme