potassium hydroxide in ethanol; water 168 h; Ambient temperature;

in MeCN-water

1: 1) CuBr*Me2S, 2) BF3*Et2O / 1) Et2O, -40 deg C, 45 min, 2) Et2O, -78 deg C, 15 min, 3) -78 deg C to RT, 45 min 2: 70 percent / 1N KOH / ethanol; H2O / 168 h / Ambient temperature View Scheme

1.1: lithium triethylborohydride / tetrahydrofuran / 2 h / -78 °C 1.2: 0.33 h 1.3: 12 h 2.1: copper(I) bromide dimethylsulfide complex / diethyl ether / 0.75 h / -40 °C 2.2: 0.5 h / -78 °C 2.3: 4 h / -78 - 20 °C 3.1: water; lithium hydroxide hydrate / ethanol / 0 °C View Scheme

1.1: 4-(N,N-dimethlyamino)pyridine / toluene / 12.25 h / 0 - 20 °C 2.1: lithium triethylborohydride / tetrahydrofuran / 2 h / -78 °C 2.2: 0.33 h 2.3: 12 h 3.1: copper(I) bromide dimethylsulfide complex / diethyl ether / 0.75 h / -40 °C 3.2: 0.5 h / -78 °C 3.3: 4 h / -78 - 20 °C 4.1: water; lithium hydroxide hydrate / ethanol / 0 °C View Scheme

1.1: thionyl chloride / methanol / 3.5 h / 0 - 20 °C 2.1: 4-(N,N-dimethlyamino)pyridine / toluene / 12.25 h / 0 - 20 °C 3.1: lithium triethylborohydride / tetrahydrofuran / 2 h / -78 °C 3.2: 0.33 h 3.3: 12 h 4.1: copper(I) bromide dimethylsulfide complex / diethyl ether / 0.75 h / -40 °C 4.2: 0.5 h / -78 °C 4.3: 4 h / -78 - 20 °C 5.1: water; lithium hydroxide hydrate / ethanol / 0 °C View Scheme

in N,N-dimethyl-formamide T=40°C;

1: 100 percent / HCl (gas) / 4 h / Ambient temperature 2: 92 percent / 1N NaOH / dioxane / 0 °C / pH: 8-9 3: 81 percent / E4NOTs / acetonitrile / anodic oxidation 4: 1) CuBr*Me2S, 2) BF3*Et2O / 1) Et2O, -40 deg C, 45 min, 2) Et2O, -78 deg C, 15 min, 3) -78 deg C to RT, 45 min 5: 70 percent / 1N KOH / ethanol; H2O / 168 h / Ambient temperature View Scheme

1: 92 percent / 1N NaOH / dioxane / 0 °C / pH: 8-9 2: 81 percent / E4NOTs / acetonitrile / anodic oxidation 3: 1) CuBr*Me2S, 2) BF3*Et2O / 1) Et2O, -40 deg C, 45 min, 2) Et2O, -78 deg C, 15 min, 3) -78 deg C to RT, 45 min 4: 70 percent / 1N KOH / ethanol; H2O / 168 h / Ambient temperature View Scheme

1: 1) CuBr*Me2S, 2) BF3*Et2O, 4) aq. HBr 2: 20 percent / dimethylformamide / 40 °C View Scheme