triethylamine in N,N-dimethyl-formamide T=0 - 20°C; 2 h;

1: 96 percent / benzyltrimethylammonium tribromide / CH2Cl2; methanol / 4.5 h / Ambient temperature 2: 69 percent / dioxane / 4 h / Ambient temperature 3: 9 percent / BuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C View Scheme

1: 69 percent / dioxane / 4 h / Ambient temperature 2: 9 percent / BuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C View Scheme

in acetone Heating;