1: rac-6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexyne With n-butyllithium in tetrahydrofuran; hexane T=-78 - 20°C; 2: ethyl iodide in tetrahydrofuran 2 h; Heating;

1: rac-6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexyne With n-butyllithium in tetrahydrofuran; hexane T=-78 - 20°C; 2: ethyl bromide With sodium iodide in tetrahydrofuran 8 h; Heating;

1: 85 percent / dimethylsulfoxide / Ambient temperature 2: 84 percent / 1.) BuLi; 2.) HMPA / tetrahydrofuran; hexane / 1.) 0-5 deg C; 2.) r.t., 30 min View Scheme