1.1: BuLi / tetrahydrofuran; hexane / 1.5 h / 20 °C 1.2: MgBr2 / tetrahydrofuran; hexane / 0.5 h / 20 °C 1.3: tetrahydrofuran; hexane / 3 h / 20 °C 2.1: NaOH / methanol; tetrahydrofuran; H2O View Scheme

1.1: BuLi / tetrahydrofuran; hexane / 1.5 h / 20 °C 1.2: MgBr2 / tetrahydrofuran; hexane / 0.5 h / 20 °C 1.3: tetrahydrofuran; hexane / 3 h / 20 °C 2.1: NaOH / methanol; tetrahydrofuran; H2O View Scheme

1: 1-(2-propyl-but-3-ynyl)-cyclohexene With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 2: With tBuOOLi in tetrahydrofuran; toluene T=-78 - 0°C; 2.5 h; 3: tri-isopropylsylil trifluoromethane sulfonate in tetrahydrofuran; toluene T=0°C; 0.5 h;