1: PPE / CH2Cl2 / 0.5 h / Heating 2: 1.) H2SO4, 2.) o-chloranil / 1.) toluene, reflux, 2h, 2.) reflux, 1h 3: 96 percent / NaBH4 / 1,2-dimethoxy-ethane / 3 h / Heating 4: 95 percent / 150 - 215 °C 5: 87 percent / KOH / acetone / Ambient temperature View Scheme

1: PPE / CH2Cl2 / 0.5 h / Heating 2: 1.) H2SO4, 2.) o-chloranil / 1.) toluene, reflux, 2h, 2.) reflux, 1h View Scheme

1: PPE / CH2Cl2 / 0.5 h / Heating 2: 1.) H2SO4, 2.) o-chloranil / 1.) toluene, reflux, 2h, 2.) reflux, 1h 3: 96 percent / NaBH4 / 1,2-dimethoxy-ethane / 3 h / Heating View Scheme