18-crown-6 ether; nonafluoro-n-butanesulfonyl fluoride; caesium carbonate in acetonitrile T=60°C; 29 h; Inert atmosphere;

1: 1-bromo-4-chloro-2-fluoro-benzene With n-butyllithium in diethyl ether; hexane T=-78°C; 0.583333 h; 2: furan in diethyl ether T=-73 - 20°C; Diels-Alder cycloaddition; Further stages.;

lanthanum; iodine in tetrahydrofuran T=25°C; 4 h;

lanthanum; iodine in tetrahydrofuran T=25°C; 4 h;

tetrabutyl ammonium fluoride in tetrahydrofuran; dichloromethane T=20°C; 1 h;

1.1: N-iodo-succinimide; [bis(acetoxy)iodo]benzene; palladium diacetate / 1,2-dichloro-ethane / 1.2 h / 70 °C / Inert atmosphere 2.1: hydrogen fluoride / tetrahydrofuran; water / 1 h / 20 °C 3.1: boron trifluoride diethyl etherate; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 1 h / 20 °C 3.2: 0 - 20 °C 4.1: tetrabutyl ammonium fluoride / tetrahydrofuran; dichloromethane / 1 h / 20 °C View Scheme

1.1: boron trifluoride diethyl etherate; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 1 h / 20 °C 1.2: 0 - 20 °C 2.1: tetrabutyl ammonium fluoride / tetrahydrofuran; dichloromethane / 1 h / 20 °C View Scheme

1.1: hydrogen fluoride / tetrahydrofuran; water / 1 h / 20 °C 2.1: boron trifluoride diethyl etherate; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 1 h / 20 °C 2.2: 0 - 20 °C 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran; dichloromethane / 1 h / 20 °C View Scheme

1.1: potassium phosphate; bis(bicyclo[2.2.1]hepta-2,5-diene)dichlorodirhodium / 1,4-dioxane / 20 °C / Inert atmosphere 2.1: N-iodo-succinimide; [bis(acetoxy)iodo]benzene; palladium diacetate / 1,2-dichloro-ethane / 1.2 h / 70 °C / Inert atmosphere 3.1: hydrogen fluoride / tetrahydrofuran; water / 1 h / 20 °C 4.1: boron trifluoride diethyl etherate; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 1 h / 20 °C 4.2: 0 - 20 °C 5.1: tetrabutyl ammonium fluoride / tetrahydrofuran; dichloromethane / 1 h / 20 °C View Scheme

isopentyl nitrite 1.) CHCl3, 15 min, reflux; 2.) dioxane 70 deg C; Multistep reaction;