2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane T=-95°C; optical yield given as percent de;

copper(II) sulfate in toluene T=70°C; 3 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: DMAP / pyridine / 12 h / Ambient temperature 2: POCl3 / CH2Cl2 / 4 h / Ambient temperature 3: 1.) n-BuLi, TMEDA / 1.) THF, hexane, -78 deg C to rt, 2.) THF, hexane, 0 deg C to rt 4: 90 percent / KHCO3 / methanol; H2O / 12 h / 40 °C 5: CuSO4*5H2O / toluene / 3 h / 70 °C View Scheme

1: POCl3 / CH2Cl2 / 4 h / Ambient temperature 2: 1.) n-BuLi, TMEDA / 1.) THF, hexane, -78 deg C to rt, 2.) THF, hexane, 0 deg C to rt 3: 90 percent / KHCO3 / methanol; H2O / 12 h / 40 °C 4: CuSO4*5H2O / toluene / 3 h / 70 °C View Scheme

1: 1.) n-BuLi, TMEDA / 1.) THF, hexane, -78 deg C to rt, 2.) THF, hexane, 0 deg C to rt 2: 90 percent / KHCO3 / methanol; H2O / 12 h / 40 °C 3: CuSO4*5H2O / toluene / 3 h / 70 °C View Scheme

1: 90 percent / KHCO3 / methanol; H2O / 12 h / 40 °C 2: CuSO4*5H2O / toluene / 3 h / 70 °C View Scheme