1: NaBH4 / methanol / 0.75 h / 0 °C 2: imidazole / dimethylformamide / 4 h / 80 °C 3: LiAlH4 / diethyl ether / 1 h / 20 °C 4: pyridine / 4 h / 25 °C 5: NaI / acetone / 16 h / 60 °C 6: 82 percent / NaH / tetrahydrofuran; hexamethylphosphoric acid triamide / 12 h / -30 - 20 °C 7: 80 percent / various solvent(s) / 3 h / 213 °C 8: 93 percent / diethyl ether / 0.08 h / -20 °C 9: CF3CO3H / CH2Cl2 / 1 h / 20 °C 10: 2N HCl / methanol; tetrahydrofuran / 3 h / 60 °C View Scheme

1: p-TsOH, CH(OCH3)3 2: 1.) LiAlH4, 2.) TsCl, Py, 3.) LiBr 3: at -75 deg C to room temperature 4: 94 percent / deketalization 5: 0 °C 6: 86 percent / CsF / acetonitrile / 1.5 h / Heating View Scheme