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

1.1: NaH / tetrahydrofuran / 20 °C 1.2: 95 percent / tetrahydrofuran / 8 h / 20 °C 2.1: LDA / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.2: 60 percent / 1,2-dibromoethane / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

1.1: NaH / tetrahydrofuran / 20 °C 1.2: 95 percent / tetrahydrofuran / 8 h / 20 °C 2.1: LDA / tetrahydrofuran; hexane / 0.5 h / -78 °C 2.2: 60 percent / 1,2-dibromoethane / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

sodium hydroxide in ethanol Heating;