1: 92 percent / butylmagnesium chloride; butyllithium / tetrahydrofuran; hexane; toluene / 0.75 h / 0 °C 2: 89 percent / butyllithium / diethyl ether; hexane / 0.25 h / -100 °C View Scheme

1: 92 percent / butylmagnesium chloride; butyllithium / tetrahydrofuran; hexane; toluene / 0.75 h / 0 °C 2: 89 percent / butyllithium / diethyl ether; hexane / 0.25 h / -100 °C 3: 93 percent / butyllithium / diethyl ether; hexane / 0.25 h / -75 °C View Scheme

n-butyllithium; n-butyl-magnesium chloride in tetrahydrofuran; hexane; toluene T=0°C; 0.75 h;