反应详情

A mixture of α-[(4-acetyl-2-methoxycarbonylphenyl)oxy]-γ-butyrolactone (2.8 g), 1,8-diazabicyclo[5,4,0]-7-undecene (0.056 g), sodium chloride (0.6 g) and N,N-dimethylformamide (28 ml) was heated at 150°-155° C. for 4 hours. The solvent was removed in vacuo and the resulting residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with water and dried. The residue obtained by removal of the solvent in vacuo was chromatographed on silica gel. The fraction eluted with dichloromethane was crystallized from ethanol to give 5-acetylspiro[benzo[b]furan-2(3H), 1'-cyclopropane]-3-one (1.15 g) as colorless crystals.

1. temperaturewas heated at 150°-155° C. for 4 hours
2. customThe solvent was removed in vacuo
3. dissolutionthe resulting residue was dissolved in ethyl acetate
4. washThe ethyl acetate solution was washed with water
5. customdried
6. customThe residue obtained by removal of the solvent in vacuo
7. customwas chromatographed on silica gel
8. washThe fraction eluted with dichloromethane
9. customwas crystallized from ethanol