反应详情

温度

90 °C

To a solution of 5-hydroxy-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-one (AU154) obtained in Example 4 (1.98 g, 10 mM) in pyridine (10 ml), phthalic anhydride (1.78 g, 12 mM) and dimethyl aminopyridine (0.05 g) were added and warmed to 90° C. for three hours, left to cool, poured onto ice-water, alkalified with potassium carbonate and extracted with ethyl acetate. The aqueous layer was acidified with hydrochloric acid and extracted with ethyl acetate, washed with brine, dried over magnesium sulfate, filtered, and concentrated. The residue was crystallized from a mixed solvent of ethyl acetate and hexane to obtain 1.80 g (53%) of 5-(2-carboxybenzoyloxy)-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-one (AU218) as colorless plates. Melting point: 158.0° to 158.5° C.

1. additionwere added
2. waitleft
3. temperatureto cool
4. additionpoured onto ice-water
5. extractionextracted with ethyl acetate
6. extractionextracted with ethyl acetate
7. washwashed with brine
8. dry with materialdried over magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated
11. customThe residue was crystallized from a mixed solvent of ethyl acetate and hexane