trifluoroacetic acid in dichloromethane T=20°C; 3 h;

1: 96 percent / H2O, sodium bicarbonate / tetrahydrofuran / 22.5 h 2: 99 percent / hexane; CH2Cl2 / 0.75 h / Heating View Scheme

1.1: lithium diisopropylamide / tetrahydrofuran; heptane / 0.25 h / -78 °C 1.2: tetrahydrofuran; heptane / 1 h / -78 °C 2.1: lithium diisopropylamide; N,N,N',N'-tetramethylethylenediamine / tetrahydrofuran; heptane / 0.17 h / -78 °C 2.2: tetrahydrofuran; heptane / 1 h / -78 °C 3.1: 1.63 g / trifluoroacetic acid / CH2Cl2 / 3 h / 20 °C View Scheme

1.1: lithium diisopropylamide; N,N,N',N'-tetramethylethylenediamine / tetrahydrofuran; heptane / 0.17 h / -78 °C 1.2: tetrahydrofuran; heptane / 1 h / -78 °C 2.1: 1.63 g / trifluoroacetic acid / CH2Cl2 / 3 h / 20 °C View Scheme

1.1: tetrahydrofuran / -78 °C / Inert atmosphere 1.2: Inert atmosphere 2.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme

1.1: sodium hydrogencarbonate / N,N-dimethyl-formamide / 20 °C / Inert atmosphere 2.1: sodium hydride / N,N-dimethyl-formamide / 20 °C / Inert atmosphere; Cooling with ice 3.1: sodium hydroxide / ethanol; water / 20 °C / Inert atmosphere 3.2: Inert atmosphere 4.1: thionyl chloride / toluene / 2 h / Inert atmosphere; Reflux 5.1: dichloromethane / 20 °C / Inert atmosphere 6.1: N,N,N',N,-tetramethylethylenediamine; tert.-butyl lithium / tetrahydrofuran / -78 °C / Inert atmosphere 6.2: 20 °C / Inert atmosphere 6.3: 20 °C / Inert atmosphere 7.1: manganese(IV) oxide; acetic acid / dichloromethane / 20 °C / Inert atmosphere 8.1: tetrahydrofuran / -78 °C / Inert atmosphere 8.2: Inert atmosphere 9.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme

1.1: manganese(IV) oxide; acetic acid / dichloromethane / 20 °C / Inert atmosphere 2.1: tetrahydrofuran / -78 °C / Inert atmosphere 2.2: Inert atmosphere 3.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme

1.1: N,N,N',N,-tetramethylethylenediamine; tert.-butyl lithium / tetrahydrofuran / -78 °C / Inert atmosphere 1.2: 20 °C / Inert atmosphere 1.3: 20 °C / Inert atmosphere 2.1: manganese(IV) oxide; acetic acid / dichloromethane / 20 °C / Inert atmosphere 3.1: tetrahydrofuran / -78 °C / Inert atmosphere 3.2: Inert atmosphere 4.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme

1.1: sodium hydride / N,N-dimethyl-formamide / 20 °C / Inert atmosphere; Cooling with ice 2.1: sodium hydroxide / ethanol; water / 20 °C / Inert atmosphere 2.2: Inert atmosphere 3.1: thionyl chloride / toluene / 2 h / Inert atmosphere; Reflux 4.1: dichloromethane / 20 °C / Inert atmosphere 5.1: N,N,N',N,-tetramethylethylenediamine; tert.-butyl lithium / tetrahydrofuran / -78 °C / Inert atmosphere 5.2: 20 °C / Inert atmosphere 5.3: 20 °C / Inert atmosphere 6.1: manganese(IV) oxide; acetic acid / dichloromethane / 20 °C / Inert atmosphere 7.1: tetrahydrofuran / -78 °C / Inert atmosphere 7.2: Inert atmosphere 8.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme

1.1: thionyl chloride / toluene / 2 h / Inert atmosphere; Reflux 2.1: dichloromethane / 20 °C / Inert atmosphere 3.1: N,N,N',N,-tetramethylethylenediamine; tert.-butyl lithium / tetrahydrofuran / -78 °C / Inert atmosphere 3.2: 20 °C / Inert atmosphere 3.3: 20 °C / Inert atmosphere 4.1: manganese(IV) oxide; acetic acid / dichloromethane / 20 °C / Inert atmosphere 5.1: tetrahydrofuran / -78 °C / Inert atmosphere 5.2: Inert atmosphere 6.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C / Inert atmosphere View Scheme