1: 1H-imidazole / dichloromethane / 1.25 h / 20 °C 2: sodium tetrahydroborate / ethanol / 1 h / 20 °C 3: toluene-4-sulfonic acid / toluene / 0.33 h / 80 °C / |Microwave irradiation 4: tetrakis(triphenylphosphine) palladium(0); sodium carbonate / toluene; ethanol; water / 80 °C 5: hydrogen fluoride; pyridine / tetrahydrofuran / 5 h / 20 °C View Scheme

1: 1H-imidazole / dichloromethane / 1.25 h / 20 °C 2: sodium tetrahydroborate / ethanol / 1 h / 20 °C 3: toluene-4-sulfonic acid / toluene / 0.33 h / 80 °C / |Microwave irradiation 4: tetrakis(triphenylphosphine) palladium(0); sodium carbonate / toluene; ethanol; water / 80 °C 5: hydrogen fluoride; pyridine / tetrahydrofuran / 5 h / 20 °C View Scheme