1: With n-butyllithium in tetrahydrofuran T=-78 - 0°C; 0.833333 h; 2: With bis(benzenesulfonyl)fluoromethane in tetrahydrofuran T=-78 - 20°C; 2.5 h;

potassium tert-butylate in tetrahydrofuran T=25°C;

1: 80 percent / Et3N*3HF; N-bromosuccinimide / CH2Cl2 / 25 °C 2: 84 percent / t-BuOK / tetrahydrofuran / 25 °C View Scheme