in acetone T=20°C; 3 h;

1: 97 percent / PPh3; CCl4 / acetonitrile / 1 h / 20 °C 2: 88 percent / acetone / 3 h / 20 °C View Scheme

1.1: conc. sulfuric acid / 4 h / 20 °C 1.2: 85 percent / aq. HPF6 / 0 °C 2.1: nBuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C 2.2: tetrahydrofuran; hexane / 0.75 h / 20 °C 2.3: 2.02 g / acetic acid / tetrahydrofuran; hexane / 2 h View Scheme