1: dimethyl(1,1-dimethylethyl)(2-propynyloxy)silane With n-butyllithium in tetrahydrofuran; hexane T=0 - 20°C; 2.5 h; 2: dibromo-difluoro-methane in tetrahydrofuran; hexane T=-78°C; 2.5 h;

1: dimethyl(1,1-dimethylethyl)(2-propynyloxy)silane With n-butyllithium in tetrahydrofuran; hexane T=0 - 20°C; 2: monobromomonochlorodifluoromethane in tetrahydrofuran; hexane T=-80°C;

1.1: 94 percent / imidazole; DMAP / dimethylformamide / 17 h / 20 °C 2.1: nBuLi / tetrahydrofuran; hexane / 0 - 20 °C 2.2: 40 percent / tetrahydrofuran; hexane / -80 °C View Scheme

n-butyllithium 1.) THF-hexane, 0 deg C, than 1 h at r.t., 2.) THF-hexane -78 deg C, 2 h; Yield given. Multistep reaction;