1.1: sodium hydroxide / methanol; water / 3 h / 20 °C 1.2: pH 1 2.1: chloroformic acid ethyl ester; triethylamine / chloroform / 1 h / -15 °C 2.2: 1 h / -15 - 20 °C 3.1: trifluoroacetic acid / 1,2-dichloro-ethane / 3 h / 20 °C 4.1: t-butyldimethylsiyl triflate; triethylamine / dichloromethane / 1.5 h / -78 °C / Inert atmosphere 4.2: 48 h / 60 °C 5.1: potassium tri-sec-butyl-borohydride / tetrahydrofuran / 1 h / -78 °C / Inert atmosphere 6.1: 4-bromooctafluorobutanetriethoxysilane; zinc diacetate / tetrahydrofuran / 8 h / 40 °C / Inert atmosphere View Scheme

1.1: sodium hydroxide / methanol; water / 3 h / 20 °C 1.2: pH 1 2.1: chloroformic acid ethyl ester; triethylamine / chloroform / 1 h / -15 °C 2.2: 1 h / -15 - 20 °C 3.1: trifluoroacetic acid / 1,2-dichloro-ethane / 3 h / 20 °C 4.1: potassium tri-sec-butyl-borohydride / tetrahydrofuran / 1 h / -78 °C / Inert atmosphere 5.1: 4-bromooctafluorobutanetriethoxysilane; zinc diacetate / tetrahydrofuran / 8 h / 40 °C / Inert atmosphere View Scheme