potassium tert-butylate in tetrahydrofuran T=20°C;

1.1: n-BuLi / tetrahydrofuran / -78 °C 1.2: NaBH4 / tetrahydrofuran / 0 °C 2.1: 95 percent / Et3N; (4-dimethylamino)pyridine / tetrahydrofuran / 2.5 h / -40 °C 3.1: 98 percent / NaI / acetone / 5.5 h / Heating 4.1: 99 percent / 3 h / 150 °C 5.1: NaH / tetrahydrofuran / 1 h / Heating 5.2: 92 percent / tetrahydrofuran / 20 h / 20 °C 6.1: 92 percent / Br2 / CHCl3 / 2 h / 20 °C 7.1: 90 percent / t-BuOK / CH2Cl2 / 24 h / 20 °C View Scheme

1.1: 95 percent / Et3N; (4-dimethylamino)pyridine / tetrahydrofuran / 2.5 h / -40 °C 2.1: 98 percent / NaI / acetone / 5.5 h / Heating 3.1: 99 percent / 3 h / 150 °C 4.1: NaH / tetrahydrofuran / 1 h / Heating 4.2: 92 percent / tetrahydrofuran / 20 h / 20 °C 5.1: 92 percent / Br2 / CHCl3 / 2 h / 20 °C 6.1: 90 percent / t-BuOK / CH2Cl2 / 24 h / 20 °C View Scheme

1.1: 99 percent / 3 h / 150 °C 2.1: NaH / tetrahydrofuran / 1 h / Heating 2.2: 92 percent / tetrahydrofuran / 20 h / 20 °C 3.1: 92 percent / Br2 / CHCl3 / 2 h / 20 °C 4.1: 90 percent / t-BuOK / CH2Cl2 / 24 h / 20 °C View Scheme

1.1: 98 percent / NaI / acetone / 5.5 h / Heating 2.1: 99 percent / 3 h / 150 °C 3.1: NaH / tetrahydrofuran / 1 h / Heating 3.2: 92 percent / tetrahydrofuran / 20 h / 20 °C 4.1: 92 percent / Br2 / CHCl3 / 2 h / 20 °C 5.1: 90 percent / t-BuOK / CH2Cl2 / 24 h / 20 °C View Scheme

1: 92 percent / Br2 / CHCl3 / 2 h / 20 °C 2: 90 percent / t-BuOK / CH2Cl2 / 24 h / 20 °C View Scheme

1.1: NaH / tetrahydrofuran / 1 h / Heating 1.2: 92 percent / tetrahydrofuran / 20 h / 20 °C 2.1: 92 percent / Br2 / CHCl3 / 2 h / 20 °C 3.1: 90 percent / t-BuOK / CH2Cl2 / 24 h / 20 °C View Scheme

1.1: NaH / tetrahydrofuran / 20 °C 1.2: 92 percent / tetrahydrofuran / 20 °C 2.1: 92 percent / Br2 / CHCl3 / 20 °C 3.1: 90 percent / t-BuOK / tetrahydrofuran / 20 °C View Scheme