2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane; water 4 h; Ambient temperature;

1.1: 27.3 g / p-TSA / methanol / 6 h / 20 °C 2.1: n-BuLi / tetrahydrofuran / 4.25 h / -15 - 0 °C 2.2: tetrahydrofuran; CH2Cl2 / -10 °C 3.1: 14.5 g / DDQ / CH2Cl2; H2O / 2 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran / 4.25 h / -15 - 0 °C 1.2: tetrahydrofuran; CH2Cl2 / -10 °C 2.1: 14.5 g / DDQ / CH2Cl2; H2O / 2 h / 20 °C View Scheme

sodium hydroxide T=55 - 60°C;

1: 95 percent / pyridine, 4-dimethylaminopyridine / CH2Cl2 / 2 h / Ambient temperature 2: 31 percent / SnCl4, conc. HNO3 / CH2Cl2 / 16 h / 0 °C 3: 94 percent / 10percent aq. KOH / ethanol / 16 h / Ambient temperature 4: 91 percent / H2 / 10percent Pd/C / ethanol / 900.07 Torr / Ambient temperature View Scheme

1: 72 percent / Br2; NaOAc; acetic acid / 8 h / 20 °C 2: 66 percent / K2CO3 / acetone / 5 h / Heating 3: 96 percent / p-TSA; m-CPBA / CH2Cl2 / 4 h / 0 - 20 °C 4: 94 percent / triethylamine / CH2Cl2; methanol / 1 h / 20 °C View Scheme

1: 72 percent / Br2; NaOAc; acetic acid / 8 h / 20 °C 2: HClO2; NaH2PO4; DMS / tetrahydrofuran; H2O / 2 h / 20 °C 3: 173.3 g / tetrahydrofuran; methanol View Scheme

1: 72 percent / Br2; NaOAc; acetic acid / 8 h / 20 °C 2: 66 percent / K2CO3 / acetone / 5 h / Heating View Scheme