反应详情

A mixture of α-[(6-acetyl-2-methoxycarbonylphenyl)oxy]-γ-butyrolactone (3.5 g), 1,8-diazabicyclo[5,4,0]-7-undecene (0.14 g) and sodium chloride (1.1 g) in N,N-dimethylformamide (66.5 ml) was stirred at 150°-160° C. for 5 hours. The solvent was distilled off under reduced pressure and the residue was subjected to chromatography on silica gel. The fraction eluted with dichloromethane was recrystallized from CHCl3 -hexane to give 7-acetylspiro[benzo[b]furan-2(3H), 1'-cyclopropane]-3-one (0.22 g) as colorless needles melting at 114°-115° C.

1. distillationThe solvent was distilled off under reduced pressure
2. washThe fraction eluted with dichloromethane
3. customwas recrystallized from CHCl3 -hexane