1.1: lithium diisopropyl amide / tetrahydrofuran / -78 °C 2.1: sodium hydroxide / ethanol / Reflux 3.1: sodium hydroxide / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 3.2: 2 h / 20 °C / Inert atmosphere 4.1: sodium hydroxide / N,N-dimethyl-formamide / 2 h / 60 °C / Inert atmosphere 5.1: hydrogenchloride / ethanol; water / Reflux View Scheme

1.1: lithium diisopropyl amide / tetrahydrofuran / 1.25 h / -78 - 20 °C / |Inert atmosphere 1.2: 14 h / 0 °C / |Inert atmosphere 2.1: potassium carbonate / N,N-dimethyl-formamide / 14 h / 20 °C / |Inert atmosphere View Scheme

1.1: LDA / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 84 percent / I2 / tetrahydrofuran; hexane / -78 - 20 °C 2.1: NaOH / ethanol / Heating View Scheme

1.1: LDA / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 92 percent / hexachloroethane / tetrahydrofuran; hexane / -78 - 20 °C 2.1: 82 percent / NaOH / ethanol / Heating View Scheme

1: With lithium diisopropyl amide in tetrahydrofuran T=-78 - 20°C; 1.25 h; Inert atmosphere; 2: With hydrogenchloride in water T=0°C; 14 h; Inert atmosphere;

1.1: LDA / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 71 percent / 1,2-dibromoethane / tetrahydrofuran; hexane / -78 - 20 °C 2.1: 94 percent / NaOH / ethanol / Heating View Scheme

1.1: lithium diisopropyl amide / tetrahydrofuran / -78 °C 2.1: sodium hydroxide / ethanol / Reflux 3.1: sodium hydroxide / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 3.2: 2 h / 20 °C / Inert atmosphere 4.1: sodium hydroxide / N,N-dimethyl-formamide / 2 h / 60 °C / Inert atmosphere 5.1: copper(l) iodide; bis-triphenylphosphine-palladium(II) chloride; diethylamine / N,N-dimethyl-formamide / 3 h / 40 °C / Inert atmosphere 6.1: sodium hydroxide / N,N-dimethyl-formamide / 5 h / 140 °C / Inert atmosphere View Scheme

1: With lithium diisopropyl amide in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: With iodine in tetrahydrofuran; hexane T=-78 - 20°C;

1: With 2,2,6,6-tetramethylpiperidinyl-lithium in tetrahydrofuran T=-78°C; 1 h; 2: With ethylene dibromide in tetrahydrofuran T=-78 - 20°C; 0.5 h;

1: With lithium diisopropyl amide in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: With 1,2,2-trichloro-1,1,2-trichloro-ethane in tetrahydrofuran; hexane T=-78 - 20°C;