1: 90 percent / PBr3, pyridine / diethyl ether / cooled, 30 min, then standing overnight, then reflux, 2 h 2: 70 percent / benzene; dimethylformamide / 16 h / Heating 3: 80 percent / NaCl / H2O; dimethylsulfoxide / 8 h / 140 - 145 °C 4: 90 percent / LiAlH4 / diethyl ether / reflux, then room temp., overnight, then reflux, 30 min View Scheme

1: 90 percent / PBr3, pyridine / diethyl ether / cooled, 30 min, then standing overnight, then reflux, 2 h 2: 70 percent / benzene; dimethylformamide / 16 h / Heating 3: 80 percent / NaCl / H2O; dimethylsulfoxide / 8 h / 140 - 145 °C 4: 90 percent / LiAlH4 / diethyl ether / reflux, then room temp., overnight, then reflux, 30 min 5: 90 percent / PBr3, pyridine / diethyl ether / reflux, 20 min, then room temp., overnight, then reflux, 2 h 6: 1)Mg / 1)THF 2)room temp., overnight, then reflux, 3 h 7: 60 percent / pyridinium chlorochromate / CH2Cl2 / 3 h / Ambient temperature View Scheme

1: 66 percent / pyridinium chlorochromate / CH2Cl2 / 3 h / low temperature 2: 1) NaH / 1) THF, oil, 2a) room temperature, 3 h, b) 50 deg C, 3 h 3: 70 percent / KOH / methanol / 10 h / Ambient temperature View Scheme

pyridinium chlorochromate in dichloromethane 3 h; low temperature;

1: 70 percent / pyridinium chlorochromate / CH2Cl2 / 2 h / Ambient temperature 2: 70 percent / dimethylsulfoxide / 1. cooling, 2h 2. room temperature, 12h 3. 50 deg C, 3h 3: 75 percent / PTS / benzene / 6 h / Heating; in a Dean and Stark water seperator 4: 90 percent / PTS / acetone / 24 h / Ambient temperature View Scheme

1: 95 percent / PPh3, Br2 / 3 h / Ambient temperature 2: 1.) t-BuLi / 1.) THF, 2.) THF, -50 deg C, 1 h 3: bipyridinium chlorochromate / CH2Cl2 / 2.5 h / Ambient temperature 4: I2 / diethyl ether / 4 h / Ambient temperature 5: NaBH4 / methanol / 0.25 h / 0 °C 6: imidazole / dimethylformamide / 2.5 h / 50 °C 7: diisobutylaluminium hydride / CH2Cl2 / 0.08 h / -78 °C 8: pyridinium chlorochromate / CH2Cl2 / 2.5 h / Ambient temperature 9: 83 percent / 48percent aq. HF / acetonitrile / 2 h / Ambient temperature View Scheme

hydrogen; Pd/C poisoned with pyridine in ethyl acetate

in diethyl ether T=0 - 20°C; homologation;

lithium aluminium tetrahydride in tetrahydrofuran T=20°C; Reduction;

1.1: n-BuLi / tetrahydrofuran; hexane / 0.67 h / -78 °C 1.2: 75 percent / tetrahydrofuran; hexane / 20 °C 2.1: 83 percent / NaBH4; 1,2-diaminoethane; hydrogen / Ni(OAc)2*4H2O / methanol / 5 h / 20 °C View Scheme