1: HBr / benzene / Heating 2: pyridinium p-toluenesulfonate / CH2Cl2 / 24 h / 20 °C View Scheme

potassium permanganate; sulfuric acid; hydrogen bromide 1.) 3 h, reflux; 2.) 20percent H2SO4, 15-20 deg C; Yield given. Multistep reaction;

1.1: HBr / benzene / Heating 2.1: pyridinium p-toluenesulfonate / CH2Cl2 / 24 h / 20 °C 3.1: magnesium / tetrahydrofuran / 3 h / 55 °C 3.2: dilithium tetrachlorocuprate(II) / tetrahydrofuran / 3 h / 0 °C 4.1: 4.5 g / pyridinium p-toluenesulfonate / methanol / 3 h / Heating View Scheme

1.1: NaH / tetrahydrofuran / Heating 2.1: acetonitrile / Heating 3.1: n-BuLi / tetrahydrofuran; hexane / 0 °C 3.2: potassium tert-butoxide / tetrahydrofuran; hexane / 0 °C 3.3: 45 percent / tetrahydrofuran; hexane / -78 - 0 °C 4.1: 57 percent / H2 / Pd/C / ethanol / 20 °C / 760 Torr View Scheme

1.1: NaH / tetrahydrofuran / Heating 2.1: acetonitrile / Heating 3.1: n-BuLi / tetrahydrofuran; hexane / 0 °C 3.2: potassium tert-butoxide / tetrahydrofuran; hexane / 0 °C 3.3: 84 percent / tetrahydrofuran; hexane / -78 - 0 °C 4.1: 91 percent / H2 / Pd/C / ethanol / 20 °C / 760 Torr View Scheme

hydrogenchloride in n-heptane T=95 - 100°C; 3 h; during the reaction was the product continuously extracted with heptane;

1: 73 percent / 48percent hydrobromic acid / benzene / 36 h / Heating 2: 98 percent / pyridinium p-toluenesulfonate / CH2Cl2 / 4 h / Ambient temperature 3: 1) magnesium, 2) Li2CuCl4 / 1) THF, 2) room temperature, 3 h 4: NaOH / ethanol / 2 h / Heating 5: 2 N HCl / ethanol / 1 h / Heating View Scheme

1: hydrogen bromide 2: alcohol / man verseift den entstandenen Ester mit alkoh. Kalilauge, kocht mit Eisessig und konz. Salzsaeure, erhitzt auf ca. 150grad und verseift das Acetylderivat 3: concentrated sulfuric acid View Scheme

1: 1.) 48 percent HBr, concd. H2SO4; 2.) KMnO4 / 1.) 3 h, reflux; 2.) 20percent H2SO4, 15-20 deg C View Scheme

1: 72 percent / 48percent HBr / benzene / 36 h / Heating 2: 98 percent / pyridinium p-toluenesulfonate / CH2Cl2 / 4 h / Ambient temperature 3: 91 percent / xylene; tetrahydrofuran; hexamethylphosphoric acid triamide / 36 h / Ambient temperature 4: 1.) 1.63N butyllithium / 1.) hexane, THF, -50 deg C, 30 min; 0 deg C, 30 min, 2.) hexane, THF, HMPA, -50 deg C, 30 min; 0 deg C, 2 h 5: 99 percent / p-toluenesulfonic acid monohydrate / methanol / 2 h / Ambient temperature 6: 92 percent / 1,3-propanediamine, Li, potassium tert-butoxide / 2 h / Ambient temperature View Scheme