1.1: sodium hydroxide / ethanol / Reflux 2.1: sodium hydroxide / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 2.2: 2 h / 20 °C / Inert atmosphere 3.1: sodium hydroxide / N,N-dimethyl-formamide / 2 h / 60 °C / Inert atmosphere 4.1: hydrogenchloride / ethanol; water / Reflux View Scheme

1: With N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran; hexane; cyclohexane T=-78°C; 2 h; 2: With 1,2,2-trichloro-1,1,2-trichloro-ethane in tetrahydrofuran; hexane; cyclohexane T=-78 - 20°C;

1.1: n-BuLi / tetrahydrofuran; hexane / -78 - 20 °C 1.2: 89 percent / hexane; tetrahydrofuran / 36 h / Heating 2.1: s-BuLi; TMEDA / cyclohexane; hexane; tetrahydrofuran / 2 h / -78 °C 2.2: 83 percent / hexachloroethane / tetrahydrofuran; hexane; cyclohexane / -78 - 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / -78 - 20 °C 1.2: 89 percent / hexane; tetrahydrofuran / 36 h / Heating 2.1: s-BuLi; TMEDA / cyclohexane; hexane; tetrahydrofuran / 2 h / -78 °C 2.2: 83 percent / hexachloroethane / tetrahydrofuran; hexane; cyclohexane / -78 - 20 °C View Scheme