1: K2CO3 / dimethylformamide 2: glacial acetic acid, triphenylphosphine / toluene / 3.5 h / Heating 3: 1.) LiOH; 2.) HCl / acetone; H2O / 1.5 h / Heating 4: 1.) 1,1'-carbonyldiimidazole / CH2Cl2 / 1.) 0 deg C, 45 min; 2.) 0 deg C to RT, 14 h View Scheme