in dichloromethane T=0 - 20°C;

1.1: n-butyllithium / tetrahydrofuran; hexane / 0.67 h / -78 °C 1.2: 80 percent / tetrahydrofuran; hexane / -78 - 20 °C 2.1: 76 percent / CH2Cl2 / 0 - 20 °C View Scheme

ammonium cerium(IV) nitrate; water in acetonitrile T=20°C; 2 h;