1.1: toluene-4-sulfonic acid / dichloromethane / 15 h / 20 °C / Inert atmosphere 2.1: n-butyllithium / tetrahydrofuran / 0.17 h / -98 °C / Inert atmosphere 2.2: 1.67 h / -98 - 20 °C / Inert atmosphere 3.1: water / tetrahydrofuran / 1 h / 20 °C 4.1: magnesium sulfate / dichloromethane / 15 h / 20 °C / Inert atmosphere 5.1: N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium / diethyl ether / -78 °C / Inert atmosphere 5.2: -98 - -78 °C / Inert atmosphere 6.1: toluene-4-sulfonic acid / diethyl ether / Inert atmosphere; Reflux 7.1: water; sodium tris(acetoxy)borohydride; acetic acid / dichloromethane / 16 h / 20 °C View Scheme

1.1: toluene-4-sulfonic acid / dichloromethane / 15 h / 20 °C / Inert atmosphere 2.1: n-butyllithium / tetrahydrofuran / 0.17 h / -98 °C / Inert atmosphere 2.2: 1.67 h / -98 - 20 °C / Inert atmosphere 3.1: water / tetrahydrofuran / 1 h / 20 °C 4.1: magnesium sulfate / dichloromethane / 15 h / 20 °C / Inert atmosphere 5.1: N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium / diethyl ether / -78 °C / Inert atmosphere 5.2: -98 - -78 °C / Inert atmosphere 6.1: toluene-4-sulfonic acid / diethyl ether / Inert atmosphere; Reflux View Scheme

1: With N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile in tetrachloromethane 3 h; Heating / reflux; 2: With sodium acetate in N,N-dimethyl-formamide T=80°C; 3: With hydrogenchloride; sodium hydroxide; water more than 3 stages;

sodium hydroxide in methanol T=20°C; 1 h;

1: dimethylformamide / 80 °C 2: 4.63 g / aq. NaOH / methanol / 1 h / 20 °C View Scheme