sodium carbonate; methanesulfonyl chloride; N-ethyl-N,N-diisopropylamine in tetrahydrofuran T=25°C; 8 h;

1: ethanol 2: sodium hydroxide / water View Scheme

sodium carbonate; methanesulfonyl chloride; N-ethyl-N,N-diisopropylamine in tetrahydrofuran; water T=10 - 57°C; 6 h;

Chiralpak AD column in ethanol; hexane Resolution of racemateHPLC conditions; optical yield given as percent ee;

1.1: benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine / tetrahydrofuran; N,N-dimethyl-formamide / 18 h / 0 - 20 °C / Inert atmosphere 2.1: 2-(trifluoromethyl)phenyllithium / tetrahydrofuran; hexane / 0.83 h / -65 - -55 °C / Inert atmosphere 2.2: 1.5 h / -65 °C / Inert atmosphere 2.3: Inert atmosphere 3.1: ethanol 4.1: sodium hydroxide / water View Scheme

1.1: 2-(trifluoromethyl)phenyllithium / tetrahydrofuran; hexane / 0.83 h / -65 - -55 °C / Inert atmosphere 1.2: 1.5 h / -65 °C / Inert atmosphere 1.3: Inert atmosphere 2.1: ethanol 3.1: sodium hydroxide / water View Scheme

1.1: pyridine; cinchonine / tetrahydrofuran / 1.75 h / -25 °C / Inert atmosphere 2.1: calcium chloride; sodium tetrahydroborate / ethanol; tetrahydrofuran / 8.5 h / -7 - 5 °C 2.2: 5 °C 3.1: N-ethyl-N,N-diisopropylamine; methanesulfonyl chloride; sodium carbonate / water; tetrahydrofuran / 6 h / 10 - 57 °C View Scheme

1.1: manganese(IV) oxide / isobutyramide / 60 h / 25 °C / Inert atmosphere 2.1: pyridine; cinchonine / tetrahydrofuran / 1.75 h / -25 °C / Inert atmosphere 3.1: calcium chloride; sodium tetrahydroborate / ethanol; tetrahydrofuran / 8.5 h / -7 - 5 °C 3.2: 5 °C 4.1: N-ethyl-N,N-diisopropylamine; methanesulfonyl chloride; sodium carbonate / water; tetrahydrofuran / 6 h / 10 - 57 °C View Scheme

1.1: calcium chloride; sodium tetrahydroborate / ethanol; tetrahydrofuran / 8.5 h / -7 - 5 °C 1.2: 5 °C 2.1: N-ethyl-N,N-diisopropylamine; methanesulfonyl chloride; sodium carbonate / water; tetrahydrofuran / 6 h / 10 - 57 °C View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane; toluene / 0.83 h / -70 - -60 °C / Inert atmosphere 1.2: 0.67 h / -70 °C / Inert atmosphere 1.3: Inert atmosphere 2.1: manganese(IV) oxide / dichloromethane / 1.5 h / 20 °C 3.1: lithium diisopropyl amide / tetrahydrofuran; hexane / 0.5 h / -70 °C / Inert atmosphere 3.2: -70 - -30 °C / Inert atmosphere 3.3: -50 °C / Inert atmosphere 4.1: sodium bis(2-methoxyethoxy)aluminium dihydride / toluene / 3 h / -15 - 0 °C 5.1: N-ethyl-N,N-diisopropylamine / tetrahydrofuran / 0.5 h / 0 - 10 °C 6.1: acetonitrile / 0.33 h / 70 °C 6.2: 6 h / 70 °C 7.1: n-butyllithium / tetrahydrofuran; hexane / 0.83 h / -78 °C / Inert atmosphere 7.2: 16 h / 0 - 20 °C / Inert atmosphere 7.3: Inert atmosphere 8.1: ethanol 9.1: sodium hydroxide / water View Scheme