lithium in tetrahydrofuran T=-45°C; 16 h; further β-bromoenamine,; Product distribution;

n-butyllithium in tetrahydrofuran; diethyl ether T=-70°C; 0.25 h;

1: 100 percent / n-butyllithium / tetrahydrofuran; diethyl ether / 0.25 h / -70 °C 2: tetrahydrofuran / 0.5 h / -65 °C 3: 1.2 N HCl / H2O / 0.5 h / Ambient temperature View Scheme