sodium tetrahydroborate; sodium hydroxide in tetrahydrofuran; methanol; water T=20°C; 15 h;

1.1: trichlorophosphate / 2 h / 45 - 50 °C 2.1: sodium tetrahydroborate / dichloromethane; methanol / 2 h / 20 °C 3.1: phosphorus tribromide / diethyl ether / 15 h / 0 - 20 °C 4.1: toluene / 24 h / |Reflux 5.1: potassium tert-butylate / tetrahydrofuran / 3.67 h / |Inert atmosphere; |Reflux 5.2: 15 h / 0 - 20 °C / |Inert atmosphere 6.1: sodium hydroxide; sodium tetrahydroborate / tetrahydrofuran; methanol; water / 15 h / 20 °C View Scheme

1.1: sodium tetrahydroborate / dichloromethane; methanol / 2 h / 20 °C 2.1: phosphorus tribromide / diethyl ether / 15 h / 0 - 20 °C 3.1: toluene / 24 h / |Reflux 4.1: potassium tert-butylate / tetrahydrofuran / 3.67 h / |Inert atmosphere; |Reflux 4.2: 15 h / 0 - 20 °C / |Inert atmosphere 5.1: sodium hydroxide; sodium tetrahydroborate / tetrahydrofuran; methanol; water / 15 h / 20 °C View Scheme

1.1: phosphorus tribromide / diethyl ether / 15 h / 0 - 20 °C 2.1: toluene / 24 h / |Reflux 3.1: potassium tert-butylate / tetrahydrofuran / 3.67 h / |Inert atmosphere; |Reflux 3.2: 15 h / 0 - 20 °C / |Inert atmosphere 4.1: sodium hydroxide; sodium tetrahydroborate / tetrahydrofuran; methanol; water / 15 h / 20 °C View Scheme

1.1: potassium tert-butylate / tetrahydrofuran / 3.67 h / |Inert atmosphere; |Reflux 1.2: 15 h / 0 - 20 °C / |Inert atmosphere 2.1: sodium hydroxide; sodium tetrahydroborate / tetrahydrofuran; methanol; water / 15 h / 20 °C View Scheme