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To a stirred solution of 4-hydroxydihydrofuran-2(3H)-one (25 g, 245 mmol) and benzyl 2,2,2-trichloroacetimidate (68.6 mL, 367 mmol) in CH2Cl2 (500 mL) and cyclohexane (500 mL) at 0° C. was added, dropwise, trifluoromethanesulfonic acid (2.175 mL, 24.49 mmol) over 10 min. The reaction mixture was stirred for 2 h at 0° C. and 48 h at room temperature. After this, it was diluted with hexanes (0.75 L), filtered and the filtrate washed with sat. aq. NaHCO3 (150 mL), dried (Na2SO4), filtered and concentrated. The resulting yellow oil was purified by flash column chromatography on silica gel column using 5-40% ethyl acetate/hexane (5% increment for every liter) to afford 4-(benzyloxy)dihydrofuran-2(3H)-one (35.52 g, 185 mmol, 75% yield) as a clear yellow oil. 1H NMR (500 MHz, CDCl3) δ: 7.34-7.39 (2 H, m), 7.29-7.34 (3 H, m), 4.53 (1 H, d, JAB=11.9 Hz), 4.52 (1 H, d, JAB=11.90 Hz), 4.34-4.41 (3 H, m), 2.64-2.68 (2 H, m).

1. filtrationfiltered
2. washthe filtrate washed with sat. aq. NaHCO3 (150 mL)
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe resulting yellow oil was purified by flash column chromatography on silica gel column