反应详情

Methyl (1aRS,7bSR)-1,1-dibromo-5-(2,2-dimethylpropionylamino)-1,1a,2,7b-tetrahydro-cyclopropa[c]chromene-4-carboxylate (Intermediate 44, 1.13 g) was suspended in ethanol (30 mL). Zinc dust (1.17 g), followed by ammonium chloride (1.31 g) were added and the reaction mixture was heated to reflux, under an atmosphere of nitrogen, for 6 hours. After cooling, the solid was filtered off and washed with ethyl acetate. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ether and cyclohexane, with a gradient of 5-12.5% to give methyl (1aRS,7bSR)-5-(2,2-dimethylpropionylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.310 g) as a colourless oil.

1. additionwere added
2. temperaturethe reaction mixture was heated
3. temperatureto reflux, under an atmosphere of nitrogen, for 6 hours
4. temperatureAfter cooling
5. filtrationthe solid was filtered off
6. washwashed with ethyl acetate
7. concentrationThe filtrate was concentrated in vacuo
8. customthe residue was purified by chromatography on silica
9. washeluting with a mixture of ether and cyclohexane, with a gradient of 5-12.5%