1: 96 percent / K2CO3 / CH2Cl2 2: 95 percent / K2CO3 / methanol 3: 81 percent / BF3*OEt2 / 3 h / 20 °C 4: 66 percent / 2.5 h / Heating 5: NaCl / dimethylsulfoxide 6: p-TSA / toluene / 3 h / Heating 7: 90 percent / DDQ / CH2Cl2 8: 92 percent / CH3CH2COOH / 2 h / 130 °C 9: 81 percent / TMSI / pyridine / 1 h / 20 °C 10: 85 percent / NaOAc / ethanol / Heating 11: 80 percent / DDQ / dioxane / Heating 12: 76 percent / O3; DMS / CH2Cl2 View Scheme