1: 2) NaBH4 / 1) ether, 4 h, reflux, 2) methanol, rt 2: 40percent aq. HF / acetonitrile / 17 h / 50 °C / or LiAlH4, 1h, reflux View Scheme

1.1: diisobutylaluminium hydride / dichloromethane / 1 h / -45 °C / |Inert atmosphere 2.1: lithium hexamethyldisilazane / tetrahydrofuran / 0.25 h / 0 °C 2.2: 1 h / 20 °C 3.1: dimethylsulfide borane complex / tetrahydrofuran / 2 h / 0 °C 3.2: 3.5 h / 0 °C 4.1: triethylamine / dichloromethane / 2 h / 0 - 20 °C 5.1: water; tetrahydrofuran / 3 h / 65 °C 6.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 3 h / 20 °C 7.1: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran / 20 °C View Scheme

1: 3.) NaBH4 2: LiAlH4 / diethyl ether / 1 h / Heating View Scheme

lithium aluminium tetrahydride in tetrahydrofuran 1 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

lithium aluminium tetrahydride in tetrahydrofuran 1 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1.1: diisobutylaluminium hydride / dichloromethane / 1 h / -45 °C / |Inert atmosphere 2.1: lithium hexamethyldisilazane / tetrahydrofuran / 0.25 h / 0 °C 2.2: 1 h / 20 °C 3.1: dimethylsulfide borane complex / tetrahydrofuran / 2 h / 0 °C 3.2: 3.5 h / 0 °C 4.1: triethylamine / dichloromethane / 2 h / 0 - 20 °C 5.1: water; tetrahydrofuran / 3 h / 65 °C 6.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 3 h / 20 °C View Scheme

1: 2) NaBH4 / 1) ether, 4 h, reflux, 2) methanol, rt 2: 40percent aq. HF / acetonitrile / 17 h / 50 °C View Scheme

hydrogen fluoride in acetonitrile T=45°C;