1: 81 percent / tetrahydrofuran / Ambient temperature 2: 1.) s-BuLi, TMEDA / 1.) cyclohexane, ether, -78 deg C, 1 h, 2.) cyclohexane, ether, a) -78 deg C, 30 min, b) 1 h View Scheme

N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium 1.) cyclohexane, ether, -78 deg C, 1 h, 2.) cyclohexane, ether, a) -78 deg C, 30 min, b) 1 h; Yield given. Multistep reaction;

manganese(IV) oxide in dichloromethane T=20°C; 72 h;

1: 100 percent / MnO2 / CH2Cl2 / 72 h / 20 °C 2: 100 percent / DMAP / tetrahydrofuran / 12 h / 20 °C View Scheme