反应详情

5-Ethenyl-4-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (1.2 g, 5.9 mmol) was added to a flask containing a stir bar. To the flask was then added dichloromethane (20 mL). The flask was placed in a cool bath of 0° C.; to the flask was poured mCPBA (1.5 g, 8.8 mmol) and the resulting mixture was stirred at room temperature for overnight; LC as well as TLC (hexanes/EtOAc=1/1) indicated that reaction had gone to completion. The solution was treated with dichloromethane and washed with NaHCO3, Na2S2O3, and water, the organic layer was then dried over Na2SO4, filtered and concentrated to dryness, it was then treated with AcOH (20 mL) and stirred overnight; LC indicated formation of cyclized product. The solvent was removed and the resulting residue was absorbed into silica gel and 6-(hydroxymethyl)-8,9-dihydro-1H-furo[3,4-f]isochromen-3(6H)-one was isolated with the solvent systems of hexanes/EtOAc (1/1). 1H-NMR (400 MHz, CDCl3) δ ppm 7.807 (d, J=8 Hz, 1H), 7.337 (d, J=8 Hz, 1H), 5.279 (s, 2H), 4.985 (s, 1H), 4.302-4.302 (m, 1H), 4.183-4.084 (m, 2H), 3.954-3.912 (m, 2H), 3.006-2.944 (m, 1H), 2.717-2.686 (m, 1H), 2.179-2.172 (m, 2H)

1. additioncontaining a stir bar
2. customThe flask was placed in a cool bath of 0° C.
3. washwashed with NaHCO3, Na2S2O3, and water
4. dry with materialthe organic layer was then dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated to dryness, it
7. additionwas then treated with AcOH (20 mL)
8. stirringstirred overnight
9. customThe solvent was removed
10. customthe resulting residue was absorbed into silica gel