a) 1,5-Pentanediol (15.6 g) was heated at reflux with 3-bromopropionic acid (50.5 g) and trace amounts of p-toluenesulfonic acid in toluene (500 mL) for 4 hours. After completion of the reaction, the toluene solution was cooled and washed with aqueous sodium acetate. Subsequently, triethylamine (50 mL) was added under reflux conditions. After cooling the reaction mixture, it was washed well with water to remove triethylamine and triethylamine hydrobromide. Toluene was removed by distillation under reduced pressure and finally purified by high-vacuum distillation (boiling point 90°C-95°C/0.1 mmHg) to afford 1,5-pentanediol diacrylate (24.0 g, 75% yield) as a light-colored liquid.
