1.1: toluene-4-sulfonic acid / toluene / 12 h / Reflux 2.1: lithium diisopropyl amide / tetrahydrofuran / -78 °C 2.2: 0.25 h 3.1: sodium tetrahydroborate / methanol / 2 h / -40 °C 4.1: pyridinium p-toluenesulfonate / dichloromethane / 3 h / Reflux 5.1: diisobutylaluminium hydride / tetrahydrofuran / 9 h / -5 °C 6.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 3 h / Reflux 7.1: dimethylaluminum chloride / hexane; dichloromethane / 0.5 h / 0 - 20 °C 8.1: 1-Me-AZADO; [bis(acetoxy)iodo]benzene / dichloromethane / 12 h / 20 °C 9.1: Wilkinson's catalyst; diethylzinc / tetrahydrofuran / 3 h / -20 °C 10.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / dichloromethane / 12 h / 0 °C 11.1: sodium cyanoborohydride; acetic acid / tetrahydrofuran / 144 h / 0 °C 12.1: hydrogenchloride / 2,2,2-trifluoroethanol; water / 0.5 h / 20 °C 13.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 12 h / 20 °C 14.1: methanol / 2.5 h / 20 °C 15.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 12 h / 20 °C 16.1: silica gel / chloroform; ethyl acetate / 0.25 h 17.1: AZADO; [bis(acetoxy)iodo]benzene / dichloromethane / 4 h / 20 °C 18.1: hydrogen fluoride / water; acetonitrile / 1.5 h / 20 °C 19.1: pyridine; dichlorotriphenylphosphorane / acetonitrile / 2 h / 20 °C View Scheme