反应详情

A mixture of ZnCl2 (42 g, 308 mmol) in acetic anhydride (100 mL) was stirred at r.t. for 2 h. The resulting solution was decanted, and to this solution was added methyl pyruvate (15.5 mL, 171 mmol) and diethyl malonate (26 mL, 171 mmol). The resulting mixture was heated at 100° C. for 1 h, then left standing at r.t. for 16 h. Ether (250 mL) was added and the mixture was washed with ice water and saturated NaHCO3. The organic layer was dried over MgSO4 and concentrated to give a dark brown oil, which was distilled under reduced pressure to give 32.3 g of the title compound as a yellow oil. 1H NMR (CDCl3, 200 MHz): δ=4.15-4.40 (m, 4H), 3.78 (s, 3H), 2.20 (s, 3H), 1.20-1.40 (m, 6H).

1. customThe resulting solution was decanted
2. temperatureThe resulting mixture was heated at 100° C. for 1 h
3. waitleft
4. waitstanding at r.t. for 16 h
5. washthe mixture was washed with ice water and saturated NaHCO3
6. dry with materialThe organic layer was dried over MgSO4
7. concentrationconcentrated
8. customto give a dark brown oil, which
9. distillationwas distilled under reduced pressure