lithium diisopropyl amide in tetrahydrofuran T=0°C; 0.5 h;

1: 92 percent / n-BuLi / diethyl ether / -70 deg C then warming up to RT 2: LDA / tetrahydrofuran / 0.5 h / 0 °C View Scheme

1: imidazole / dimethylformamide 2: 92 percent / n-BuLi / diethyl ether / -70 deg C then warming up to RT 3: LDA / tetrahydrofuran / 0.5 h / 0 °C View Scheme