chloroformic acid ethyl ester; potassium carbonate in benzene

2: ClCO2Et, K2CO3 / benzene View Scheme

1: TBABr; KI; K2CO3 / acetonitrile / Heating 2: aq. HCl / 0.5 h 3: 96 percent / K2CO3 / CH2Cl2 4: 95 percent / K2CO3 / methanol 5: 81 percent / BF3*OEt2 / 3 h / 20 °C 6: 66 percent / 2.5 h / Heating 7: NaCl / dimethylsulfoxide 8: p-TSA / toluene / 3 h / Heating 9: 90 percent / DDQ / CH2Cl2 10: 92 percent / CH3CH2COOH / 2 h / 130 °C 11: 81 percent / TMSI / pyridine / 1 h / 20 °C 12: 85 percent / NaOAc / ethanol / Heating 13: 80 percent / DDQ / dioxane / Heating 14: 76 percent / O3; DMS / CH2Cl2 View Scheme