1: 97 percent / NaOH / aq. ethanol / 5 h / Ambient temperature 2: 1)oxalyl chloride, DMSO, 2)triethylamine / 1) CH2Cl2, -60 deg C, 15 min, 2) CH2Cl2, -60 deg C, 5 min, then to r.t. 3: 1) butyllithium / 1) THF, hexane, 25 deg C for 1 h, then r.t. 1.5 h, 2) THF, hexane, 25 deg C, 1.5 h, then r.t. 1 h View Scheme