titanium tetrachloride in tetrahydrofuran; water; benzene

in tetrahydrofuran; water; benzene

1.1: 0.61 g / sodium nitrite; AcOH / 3 h / 20 °C 2.1: BuLi / tetrahydrofuran; hexane / 0.25 h / -78 °C 2.2: 82 percent / tetrahydrofuran; hexane / -78 - 20 °C 3.1: BuLi / tetrahydrofuran; hexane / 0.25 h / -78 °C 3.2: 92 percent / tetrahydrofuran; hexane / -78 - 20 °C 4.1: 74 percent / Na/Hg; K2HPO4 / acetonitrile; ethanol View Scheme

acetic acid; sodium nitrite T=20°C; 3 h;