反应详情

温度

60 °C

5.1 g α-hydroxyisovaleric acid (43 mmol) and 4.85 mL 2-bromopropionyl bromide (45 mmol) were stirred at 75° C. under nitrogen for 12 h. 300 mL acetone and 12 mL anhydrous triethylamine (86 mmol) were added to the mixture and the solution was stirred for 3 h at 60° C. After filtration of the triethylammonium bromide salts, acetone was distilled off and the resulting mixture was dissolved in 500 mL ethyl acetate:hexane mixture (1:1). After filtration over silica gel the solvents were distilled off, and the remaining crude product was recrystallized from hexane. 1H NMR (500 MHz, CDCl3): δ 5.0 (q, 1H), 4.76 (d, 1H), 2.5 (m, 1H), 1.66 (d, 3H), 1.16 (d, 3H), 1.06 (d, 3H). 13C NMR (500 MHz, CDCl3): δ 167.59, 166.16, 79.83, 72.10, 29.24, 18.51, 15.86, 15.79. ELEM. ANAL. Calcd. for C8H12O4: C, 55.81; H, 6.98. Found: C, 55.55; H, 6.99. Yield: 35%.

1. filtrationAfter filtration of the triethylammonium bromide salts, acetone
2. distillationwas distilled off
3. dissolutionthe resulting mixture was dissolved in 500 mL ethyl acetate
4. filtrationAfter filtration over silica gel the solvents
5. distillationwere distilled off
6. customthe remaining crude product was recrystallized from hexane