Multi-step reaction with 5 steps 1: 1.) DMSO, (COCl)2 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min; 2.) CH2Cl2, -78 to 0 deg C2: 35 percent / K2CO3, 18-crown-6 / toluene / 80 °C3: H2O / PPTS / tetrahydrofuran / 1.5 h / Heating4: PCC, sodium acetate / CH2Cl2 / 2.5 h5: 1.) LDA, 1,10-phenanthroline / 1.) THF, -78 deg C, 15 min; 2.) THF, -20 deg C, 5 min.  

Multi-step reaction with 3 steps 1: 1.) DMSO, (COCl)2 2.) Et3N / 1.) CH2Cl2, -78 deg C, 30 min; 2.) CH2Cl2, -78 to 0 deg C2: 35 percent / K2CO3, 18-crown-6 / toluene / 80 °C3: H2O / PPTS / tetrahydrofuran / 1.5 h / Heating