1. Pyridine-sulfur trioxide complex (51.3 g, 316 mmol) was slowly added to a solution of dichloromethane (77 mL) containing 1,3-bis(benzyloxy)-2-propanol (20.0 g, 73.4 mmol), triethylamine (49.8 mL, 358 mmol), and dimethyl sulfoxide (25.0 mL, 352 mmol) at 0 °C.
2. The reaction mixture was gradually warmed to room temperature and stirred continuously for 2 hours.
3. Upon completion of the reaction, the mixture was transferred to a dispensing funnel and partitioned with ethyl acetate (250 mL) and water (500 mL).
4. The organic phase was washed sequentially with 2M aqueous hydrochloric acid (2 x 250mL), water (2 x 200mL) and saturated aqueous sodium chloride (500mL).
5. The washed organic layer was dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to afford the intermediate 1,3-bis(benzyloxy)propan-2-one (20.8 g, 77.0 mmol) as an orange oil.
6. The resulting intermediate was dissolved in tetrahydrofuran (77 mL), cooled to 0 °C, and allylmagnesium chloride (2.0 M tetrahydrofuran solution, 38.5 mL, 77.0 mmol) was slowly added.
7. The reaction mixture was gradually warmed to room temperature and stirred for 16 hours.
8. At the end of the reaction, 1 M aqueous hydrochloric acid (500 mL) was added slowly to quench the reaction.
9. The reaction mixture was extracted with ether (3 x 200 mL), the organic layers were combined and washed with water (2 x 150 mL).
10. The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure.
11. Purification by silica gel column chromatography (elution gradient: 0 to 80% ethyl acetate in heptane) afforded the target product 1,3-bis(benzyloxy)propan-2-one (17.0 g, 54.4 mmol, 74%) as a colorless oil. 12. The product was analyzed by LCMS and LAS.
12. The product was confirmed by LCMS and 1H NMR: LCMS m/z 335.4 [M + Na]+; 1H NMR (400 MHz, CDCl3) δ 7.27-7.38 (m, 10H), 5.78-5.93 (m, 1H), 5.04-5.14 (m, 2H), 4.54 (s, 4H), 3.39-3.52 (m, 4H), 2.36-3.52 (m, 4H). , 4H), 2.36 (dt, J = 7.4, 1.1Hz, 2H).
