1: oxalyl chloride / dimethylformamide; CH2Cl2 / 1 h / Heating 2: NEt3 / tetrahydrofuran / Ambient temperature 3: DMAP / tetrahydrofuran / 0 - 20 °C 4: toluene / 18 h / 200 °C 5: K2CO3 / 14 h / Ambient temperature 6: 76 percent / Mg, MeOH / 2.5 h / Heating 7: t-BuOK / benzene / 5 h / Heating 8: AcOH, aq. HCl / 1 h / Heating 9: 5percent aq. NaOH / methanol / 1 h / Heating 10: aq. Hg(ClO4)2 / tetrahydrofuran / 1 h / Ambient temperature View Scheme