1: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / dioxane / Heating 2: 95 percent / DIBAL / toluene / 0 - 20 °C 3: 90 percent / silver(I) oxide / H2O; dioxane; ethanol / 0.5 h / 75 °C View Scheme

1: 67 percent / S, 10percent Pd-C / various solvent(s) / 2 h / Heating 2: 67 percent / Br2 / CCl4 / 3 h / 60 °C / Irradiation 3: 1.25 h / 60 °C 4: 2N HCl / 0.08 h View Scheme

1: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / dioxane / Heating 2: 95 percent / DIBAL / toluene / 0 - 20 °C View Scheme

palladium on activated charcoal in various solvent(s) 2 h; Heating;