tetrabutyl ammonium fluoride in tetrahydrofuran Yield given;

tetrabutyl ammonium fluoride in tetrahydrofuran Yield given;

1: imidazole / dimethylformamide / 1.5 h / 20 °C 2: liq. SO2 / diethyl ether / 0.5 h / Heating 3: 1.) ozone 2.) PPh3 / 1.) CH2Cl2, MeOH, -60 deg C, 40 min. 2.) CH2Cl2, MeOH, -60 to 0 deg C 4: 90 percent / NaHCO3 / ethanol / 1.5 h / Heating View Scheme

1H-imidazole in dichloromethane 6 h; Ambient temperature; Yield given;

1H-imidazole in N,N-dimethyl-formamide T=20°C; 1.5 h; Yield given. Yields of byproduct given;