1: trimethyl-oxo-sulfonium iodide With sodium hydride in dimethyl sulfoxide 0.5 h; 2: 6-fluoro-3,4-dihydro-2H-1-benzopyran-2-carboxaldehyde in dichloromethane; dimethyl sulfoxide T=20 - 25°C; 1 h;

1: With sodium hydroxide in water; isopropyl alcohol T=0°C; 1.5 h; Inert atmosphere; 2: With acetic acid in water; isopropyl alcohol; toluene

1: With sodium hydride in tert-butyl methyl ether; dimethyl sulfoxide T=50°C; 1 h; Inert atmosphere; 2: With p-toluenesulfonyl chloride in tert-butyl methyl ether 1 h; Inert atmosphere; Reagent/catalystSolvent;

1: With n-butyllithium in tetrahydrofuran; hexane T=-85 - -75°C; 2: With borane in tetrahydrofuran; hexane T=-80 - -70°C; 3: With water; sodium hydroxide in tetrahydrofuran; hexane 2 h; Reflux;

1: trimethyl-sulfonium iodide With sodium hydride in dimethyl sulfoxide cooling; 2: 6-fluoro-3,4-dihydro-2H-1-benzopyran-2-carboxaldehyde in dimethyl sulfoxide T=20°C; 1 h;

1.1: 86 percent / H2 / Pd/C / acetic acid / 70 - 80 °C / 15001.2 Torr 2.1: Et3N; ClCOOEt / tetrahydrofuran / 10 h / 20 °C 2.2: 90 percent / NaBH4 / tetrahydrofuran; H2O / 5 h / 20 °C 3.1: 78 percent / pyridinium chloroformate/SiO2 / CH2Cl2 / 1.5 h / 20 °C 4.1: NaH / dimethylsulfoxide / cooling 4.2: 100 percent / dimethylsulfoxide / 1 h / 20 °C View Scheme

1.1: Et3N; ClCOOEt / tetrahydrofuran / 10 h / 20 °C 1.2: 90 percent / NaBH4 / tetrahydrofuran; H2O / 5 h / 20 °C 2.1: 78 percent / pyridinium chloroformate/SiO2 / CH2Cl2 / 1.5 h / 20 °C 3.1: NaH / dimethylsulfoxide / cooling 3.2: 100 percent / dimethylsulfoxide / 1 h / 20 °C View Scheme

1.1: 78 percent / pyridinium chloroformate/SiO2 / CH2Cl2 / 1.5 h / 20 °C 2.1: NaH / dimethylsulfoxide / cooling 2.2: 100 percent / dimethylsulfoxide / 1 h / 20 °C View Scheme

1.1: sodium methylate; methanol / tetrahydrofuran / 5 - 25 °C 1.2: 5 - 15 °C 1.3: Reflux 2.1: hydrogen / 5 palladium on charcoal / tetrahydrofuran / 45 - 55 °C / 3000.3 Torr 3.1: n-butyllithium / hexane; tetrahydrofuran / -85 - -75 °C 3.2: -80 - 0 °C 4.1: ethanol; sodium tetrahydroborate / 2 h / 0 °C / Inert atmosphere 5.1: sodium hydroxide / isopropyl alcohol; water / 1.5 h / 0 °C / Inert atmosphere View Scheme

1.1: n-butyllithium / hexane; tetrahydrofuran / -85 - -75 °C 1.2: -80 - 0 °C 2.1: ethanol; sodium tetrahydroborate / 2 h / 0 °C / Inert atmosphere 3.1: sodium hydroxide / isopropyl alcohol; water / 1.5 h / 0 °C / Inert atmosphere View Scheme