1.1: TMEDA / diethyl ether; pentane / 0.5 h / 20 °C 2.1: TMEDA; n-BuLi / 1 h / -78 °C 2.2: 1 h / -78 °C 2.3: 0.155 g / NaOH / ethanol / 2 h / 20 °C View Scheme

4-(N,N-dimethlyamino)pyridine in tetrahydrofuran T=60°C; 24 h;