反应详情

温度

50 °C

To a mixture of 9.54 g (70 mmol) of anhydrous ZnCl2, 53.9 mL (500 mmol) of methyl acetoacetate and 55 mL (750 mmol) of acetone are added 64 mL of acetic anhydride. The reaction medium is then heated for 3 days at 50° C., and then diluted with 1 L of DCM and washed with water (3×100 mL). The organic phase is dried over Na2SO4, filtered and then concentrated under reduced pressure. The residue obtained is purified by chromatography on a column of silica gel, eluting with a cyclohexane/EtOAc gradient of 0 to 10% EtOAc. After concentrating under reduced pressure, 51.5 g of methyl 2-acetyl-3-methylbut-2-enoate are obtained in the form of a colourless oil.

1. washwashed with water (3×100 mL)
2. dry with materialThe organic phase is dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customThe residue obtained
6. customis purified by chromatography on a column of silica gel
7. washeluting with a cyclohexane/EtOAc gradient of 0 to 10% EtOAc
8. concentrationAfter concentrating under reduced pressure, 51.5 g of methyl 2-acetyl-3-methylbut-2-enoate
9. customare obtained in the form of a colourless oil