1.1: trifluoroacetic acid / methanol / 3 h / 0 °C / Inert atmosphere 2.1: trifluoroacetic acid / toluene / 0.5 h / 140 °C / Microwave irradiation 2.2: pH 8 View Scheme

1.1: chloroformic acid ethyl ester; potassium carbonate / tetrahydrofuran / 24 h / -78 - 20 °C / Inert atmosphere 2.1: sodium tetrahydroborate / tetrahydrofuran / 18 h / Reflux; Inert atmosphere 3.1: lithium diisopropyl amide / tetrahydrofuran; hexane / 1 h / -78 °C / Inert atmosphere 3.2: -78 - 20 °C / Inert atmosphere 4.1: trifluoroacetic acid / methanol / 3 h / 0 °C / Inert atmosphere 5.1: trifluoroacetic acid / toluene / 0.5 h / 140 °C / Microwave irradiation 5.2: pH 8 View Scheme

1.1: sodium tetrahydroborate / tetrahydrofuran / 18 h / Reflux; Inert atmosphere 2.1: lithium diisopropyl amide / tetrahydrofuran; hexane / 1 h / -78 °C / Inert atmosphere 2.2: -78 - 20 °C / Inert atmosphere 3.1: trifluoroacetic acid / methanol / 3 h / 0 °C / Inert atmosphere 4.1: trifluoroacetic acid / toluene / 0.5 h / 140 °C / Microwave irradiation 4.2: pH 8 View Scheme

1.1: lithium diisopropyl amide / tetrahydrofuran; hexane / 1 h / -78 °C / Inert atmosphere 1.2: -78 - 20 °C / Inert atmosphere 2.1: trifluoroacetic acid / methanol / 3 h / 0 °C / Inert atmosphere 3.1: trifluoroacetic acid / toluene / 0.5 h / 140 °C / Microwave irradiation 3.2: pH 8 View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane / 2 h / 0 - 5 °C / Inert atmosphere 1.2: 4 h / 20 °C / Inert atmosphere 2.1: chloroformic acid ethyl ester; potassium carbonate / tetrahydrofuran / 24 h / -78 - 20 °C / Inert atmosphere 3.1: sodium tetrahydroborate / tetrahydrofuran / 18 h / Reflux; Inert atmosphere 4.1: lithium diisopropyl amide / tetrahydrofuran; hexane / 1 h / -78 °C / Inert atmosphere 4.2: -78 - 20 °C / Inert atmosphere 5.1: trifluoroacetic acid / methanol / 3 h / 0 °C / Inert atmosphere 6.1: trifluoroacetic acid / toluene / 0.5 h / 140 °C / Microwave irradiation 6.2: pH 8 View Scheme

1: water; sodium hydroxide / ethanol / 3 h / 20 °C 2: thionyl chloride / dichloromethane / 1.5 h / 0 - 20 °C 3: sodium hydrogencarbonate / dichloromethane / 1.5 h / 20 °C View Scheme

in methanol

diethyl ether; chloroform

in methanol; diethyl ether 48 h;

in methanol; diethyl ether 48 h;