1: sulfuric acid / 20 h / Reflux 2: potassium carbonate / acetone / 20 h / Reflux 3: diisobutylaluminium hydride / toluene / 0 - 20 °C / Inert atmosphere 4: 2,3-dicyano-5,6-dichloro-p-benzoquinone / 1,4-dioxane / 1 h / Inert atmosphere View Scheme

1: potassium carbonate / acetone / 20 h / Reflux 2: diisobutylaluminium hydride / toluene / 0 - 20 °C / Inert atmosphere 3: 2,3-dicyano-5,6-dichloro-p-benzoquinone / 1,4-dioxane / 1 h / Inert atmosphere View Scheme