To a solution of anhydrous ethylene glycol (10 g, 161.1 mmol) in anhydrous THF (40 mL) was added sodium metal (62.0 mg, 2.70 mmol) and stirred at room temperature for 2 hours.Add tert-butyl acrylate (6.90, 53.7 mmol) and stir overnight.After quenching with water, the solvent was THF dried under reduced pressure, and extracted with ethyl acetate and water.The organic layer was separated, washed with brine, and dried over Na 2 SO 4.After filtration and evaporation, the residue was purified by silica gel column chromatography (petroleum ether/ethyl acetate = 2:1) to obtain a colorless oil 44 (5.0 g, 26.3 mmol, 49% yield)