4-Fluorobenzyl bromide → 2-(5-(4-Fluoro-benzyl)-furan-2-yl)-[1,3]dioxolane

To a tetrahydrofuran (50 mL) solution of 2-(1,3-dioxolan-2-yl-furan (5 g, 35.7 mmol) was added n-butyl lithium (15.6 mL, 2.64 M hexane solution, 41.1 mmol) at −78° C., which was stirred for 1 hour at that temperature. A tetrahydrofuran solution of 4-fluorobenzyl bromide (6.9 g, 36.5 mmol) was added dropwise to this mixture, which was stirred for another hour at −78° C. The mixture was raised to room temperature and partitioned into ethyl acetate and a saturated ammonium chloride aqueous solution. The organic layer was separated, washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, and filtered. The filtrate was concentrated under a reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate:heptane=1:10 to 1:3) to obtain the title compound (4.51 g, 51%).