tetrabutyl ammonium fluoride in tetrahydrofuran T=20°C; 0.333333 h;

hydrogenchloride; acetic acid T=100°C;

1.1: 96 percent / imidazole / dimethylformamide / 18 h / 20 °C 2.1: 52 percent / tetrahydrofuran / 0.67 h / Heating 3.1: TiCl4 / CH2Cl2 / 0.25 h / -78 °C 3.2: 7.2 percent / CH2Cl2 / 5 h / -78 °C 4.1: 76 percent / Bu4NF / tetrahydrofuran / 0.33 h / 20 °C View Scheme

1.1: 52 percent / tetrahydrofuran / 0.67 h / Heating 2.1: TiCl4 / CH2Cl2 / 0.25 h / -78 °C 2.2: 7.2 percent / CH2Cl2 / 5 h / -78 °C 3.1: 76 percent / Bu4NF / tetrahydrofuran / 0.33 h / 20 °C View Scheme