acetic acid 24 h; Ambient temperature;

n-butyllithium in tetrahydrofuran; hexane 0.5 h; Ambient temperature;

1: 92 percent / NaI, 18-crown-6 / toluene; dimethylsulfoxide / 6 h / 90 - 100 °C 2: 83 percent / tetrahydrofuran / 24 h / Heating 3: 65 percent / n-BuLi / tetrahydrofuran; hexane / 0.5 h / Ambient temperature View Scheme

1: 83 percent / tetrahydrofuran / 24 h / Heating 2: 65 percent / n-BuLi / tetrahydrofuran; hexane / 0.5 h / Ambient temperature View Scheme