反应详情

温度

25 °C

To a solution of 4-methyl-2-pentenoic acid (24.0 g, 210 mmol; commercially available from TCI America) in acetone (300 mL) was added K2CO3 (55.8 g, 404 mmol) and the reaction was stirred at 25° C. for 30 min. A solution of benzyl bromide (25.2 mL, 212 mmol; commercially available from Sigma Aldrich) in acetone (100 mL) was then added drop-wise. The reaction mixture was subsequently heated to reflux for 16 hrs. After cooling to 25° C., the acetone was removed under reduced pressure and ether (300 mL) and water (300 mL) were added and the organic layer was separated, washed with brine and dried over Na2SO4. After concentration, the crude product was subjected to silica gel chromatography (1-5% Ether/Hex) to afford 4-methyl-pent-2-enoic acid benzyl ester (40.5 g, 98%): H-NMR (CDCI3) δ 7.36-7.28 (m, 5 H), 6.96 (dd, 1 H), 5.79 (d, 1 H), 5.14 (s, 2 H), 2.45-2.40 (m, 1 H), 1.01 (d, 6 H).

1. temperatureThe reaction mixture was subsequently heated
2. temperatureto reflux for 16 hrs
3. temperatureAfter cooling to 25° C.
4. customthe acetone was removed under reduced pressure and ether (300 mL) and water (300 mL)
5. additionwere added
6. customthe organic layer was separated
7. washwashed with brine
8. dry with materialdried over Na2SO4
9. concentrationAfter concentration