反应详情

A mixture of ZnCl2 (53 g, 388 mmol) in acetic anhydride (120 mL) was stirred at r.t. for 2 h. The resulting solution was decanted, and to this solution was added ethyl pyruvate (25 g, 215 mmol) and dimethyl malonate (25 mL, 215 mmol). The resulting mixture was heated at 100° C. for 1 h, then left standing at r.t. for 16 h. Ether (300 mL) was added and the mixture was washed with ice water (5×300 mL) and saturated NaHCO3 (2×300 mL). The organic layer was dried over MgSO4 and concentrated to give a dark brown oil, which was distilled under reduced pressure to give 34.1 g of the title compound as an orange oil. 1H NMR (CDCl3, 200 MHz): δ=4.26 (q, 2H, J=7.0 Hz), 3.82 (s, 3H), 3.79 (s, 3H), 2.22 (s, 3H), 1.32 (t, 3H, J=7.2 Hz).

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 (5×300 mL) and saturated NaHCO3 (2×300 mL)
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