1: hydrogenchloride; water / tetrahydrofuran / 1.2 h / Inert atmosphere; Reflux 2: sodium tetrahydroborate / methanol / 0.67 h / 0 - 20 °C / Inert atmosphere View Scheme

1: hydrogenchloride; water / tetrahydrofuran / |Reflux 2: benzene / 20 °C / |Molecular sieve; |Inert atmosphere 3: copper(l) iodide; K3PO4 / N,N-dimethyl-formamide / 110 °C / |Inert atmosphere View Scheme

1: 93.2 percent / p-TsOH / 65 h / Heating 2: 1.) n-BuLi / 1.) THF, hexane, 1 h, -78 deg C, 2.) THF, 4 h, -78 deg C, 2.b) 30 min, room temperature 3: 43.4 percent / 0.2 N aq. HCl / dioxane / 24 h / Ambient temperature 4: 60.7 percent / NEt3, methansulfonsaeurechlorid / CH2Cl2 / 1 h / -15 °C View Scheme

1: 93.2 percent / p-TsOH / 65 h / Heating 2: 1.) n-BuLi / 1.) THF, hexane, 1 h, -78 deg C, 2.a) THF, 2 h, -78 deg C, 2.b) 30 min, room temperature 3: 41.6 percent / 0.2 N aq. HCl / dioxane / 90 h / Ambient temperature 4: 54.3 percent / NEt3, methansulfonsaeurechlorid / CH2Cl2 / 3 h / temperature < 15 deg C View Scheme

1: 93.2 percent / p-TsOH / 65 h / Heating 2: 1.) n-BuLi / 1.) THF, hexane, 30 min, -78 deg C, 2.a) THF, 1 h, -78 deg C, 2.b) room temperature View Scheme

1: 93.2 percent / p-TsOH / 65 h / Heating 2: 1.) n-BuLi / 1.) THF, hexane, 1 h, -78 deg C, 2.a) THF, 2 h, -78 deg C, 2.b) 30 min, room temperature 3: 41.6 percent / 0.2 N aq. HCl / dioxane / 90 h / Ambient temperature 4: 36.3 percent / pyridiniumdichromat / CH2Cl2 / 18 h View Scheme

1: hydrogenchloride; water / tetrahydrofuran / 1.2 h / Inert atmosphere; Reflux 2: sodium tetrahydroborate / methanol / 0.67 h / 0 - 20 °C / Inert atmosphere 3: tetrachloromethane; triethylamine; triphenylphosphine / N,N-dimethyl-formamide / 3 h / 20 °C / Inert atmosphere View Scheme

hydrogenchloride; water in tetrahydrofuran 1.2 h; Inert atmosphereReflux;