1: 85 percent / K2CO3, O2 / methanol / 24 h 2: 80 percent / 2N aq. H2SO4 / 1,2-dimethoxy-ethane / 24 h / 50 °C View Scheme

1: 88 percent / H2SO4 / 1,2-dimethoxy-ethane / 24 h / 50 °C 2: 2.) p-toluenesulfonic acid / 1.) toluene, ref;ux, 30 min, 2.) toluene, reflux, 3 h 3: 41 percent / O2, cupric chloride, dimethylamine / dimethylformamide; H2O View Scheme