1: toluene-4-sulfonic acid / benzene / 8 h / Reflux 2: diisobutylaluminium hydride / dichloromethane; toluene / 3 h / -78 °C 3: triethylamine / 12 h / 20 °C 4: methanesulfonyl chloride; triethylamine / dichloromethane / 0 - 20 °C 5: sodium tetrahydroborate / ethanol / 0 - 20 °C 6: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 20 °C 7: triethylamine / tetrahydrofuran / 0 - 20 °C 8: trifluoroacetic acid / 1,2-dichloro-ethane / 8 h / 50 °C 9: triethylamine / dichloromethane / 0 - 20 °C 10: palladium diacetate; p-benozquinone / acetonitrile / 0 - 50 °C 11: L-Selectridereg; / tetrahydrofuran / -78 - 20 °C 12: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 50 °C View Scheme

1: toluene-4-sulfonic acid / benzene / 8 h / Reflux 2: diisobutylaluminium hydride / dichloromethane; toluene / 3 h / -78 °C 3: triethylamine / 12 h / 20 °C 4: methanesulfonyl chloride; triethylamine / dichloromethane / 0 - 20 °C 5: sodium tetrahydroborate / ethanol / 0 - 20 °C 6: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 20 °C 7: triethylamine / tetrahydrofuran / 0 - 20 °C 8: trifluoroacetic acid / 1,2-dichloro-ethane / 8 h / 50 °C 9: L-Selectridereg; / tetrahydrofuran / -78 - 20 °C 10: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 45 °C View Scheme