1: 88.5 percent / oxalyl chloride, dimethylsulfoxide / CH2Cl2 / 15 h / -60 °C 2: 1.) n-butyllithium / 1.) tetrahydrofuran, hexane, 2 h, room temperature, 2.) reflux, 18 h, THF 3: 100 percent / PPTS / ethanol / 6 h / Heating 4: 96 percent / dimethylsulfoxide, triethylamine / diethyl ether / 4.5 h / Ambient temperature 5: 100 percent / 0.17 h / 600 °C 6: 92 percent / palladium acetate, p-benzoquinone / acetonitrile / 6 h / Ambient temperature View Scheme