1: With 4 A molecular sieve; tetrabutyl ammonium fluoride in tetrahydrofuran; pentane T=-78 - 20°C; 2: With sodium hydrogencarbonate in tetrahydrofuran; pentane T=0°C; Further stages.;

1.1: LiHMDS / tetrahydrofuran / -78 °C 1.2: 80 percent / tetrahydrofuran / 20 °C 2.1: 74 percent / OsO4; NaIO4; H2O / tetrahydrofuran / 20 °C 3.1: methanol / 1 h / 20 °C 3.2: magnesium sulfate / methanol / 4 h / 20 °C 3.3: NaBH4 / methanol / 1 h / 20 °C 4.1: sodium amide / toluene / 24 h / Heating 5.1: 73 percent / TFA / CH2Cl2 / 20 °C View Scheme

1.1: LiHMDS / tetrahydrofuran / -78 °C 1.2: 80 percent / tetrahydrofuran / 20 °C 2.1: 74 percent / OsO4; NaIO4; H2O / tetrahydrofuran / 20 °C 3.1: methanol / 20 °C 3.2: magnesium sulfate / methanol / 20 °C 3.3: NaBH4 / methanol / 20 °C 4.1: sodium amide / toluene / Heating 5.1: 76 percent / TFA / CH2Cl2 / 20 °C View Scheme

1.1: LiHMDS / tetrahydrofuran / -78 °C 1.2: 80 percent / tetrahydrofuran / 20 °C 2.1: 74 percent / OsO4; NaIO4; H2O / tetrahydrofuran / 20 °C 3.1: methanol / 20 °C 3.2: magnesium sulfate / methanol / 20 °C 3.3: NaBH4 / methanol / 20 °C 4.1: sodium amide / toluene / Heating 5.1: 80 percent / TFA / CH2Cl2 / 20 °C View Scheme

1: diethyl ether / 3 h / 0 - 20 °C 2: hydrogenchloride / water; ethyl acetate / 20 °C / Inert atmosphere View Scheme

1: 92 percent / LiBH4 / tetrahydrofuran / 15 h / 5 °C 2: 98 percent / TEA, 4-DMAP / dimethylformamide / 3 h / Ambient temperature 3: 90 percent / RuO2 hydrate, 10percent aqueous NaIO4 / ethyl acetate / 1 h / Ambient temperature 4: 1.) n-butyllithium, diisopropylamine / 1.) THF, -78 deg C, 30 min; 2.) THF, -78 deg C, 1h; 3.) room temperature, 1h 5: 78 percent / p-toluenesulphonic acid / methanol / 2 h / Ambient temperature 6: 1.) pyridinium dichromate; 2.) DCC, 4-DMAP / 1.) DMF, 15 h, 40 deg C; 2.) CH2Cl2, 3 h, room temperature 7: 69 percent / TEA, benzyl alcohol / 24 h / 105 °C 8: hydrogen / 10percent Pd/C / ethanol / Ambient temperature 9: 90 percent / TFA / CH2Cl2 / 0.5 h / Ambient temperature View Scheme