sodium hydride in tetrahydrofuran 1. 0 deg C 2. 1h, room temperature;

n-butyllithium in ethylene glycol dimethyl ether; hexane T=-5 - 0°C; 0.5 h;

1: 83 percent / sodium hydride / dimethylsulfoxide; dimethylformamide / 0.5 h / Ambient temperature 2: 40 percent / n-butyllithium / 1,2-dimethoxy-ethane; hexane / 0.5 h / -5 - 0 °C View Scheme