反应详情

温度

-30 °C

Potassium tert-butoxide (96.0 mg, 0.85 mmol) was added to a suspension of triphenylmethylphosphonium bromide (305 mg, 0.85 mmol) in toluene (3.00 mL) while stirring at −30° C. under N2 atmosphere. After stirring for 1 hour at −30° C., a solution of methyl 2,2-dimethyl-4-oxo-3,4-dihydro-2H-chromene-6-carboxylate (100 mg, 0.43 mmol) in toluene (2.00 mL) was added slowly via a syringe. The suspension was stirred for a further 30 minutes at −30° C. and then heated to reflux overnight. The mixture was allowed to cool to room temperature, diluted with EtOAc (50.0 mL) and washed with water (10.0 mL). The organic layer was dried over Na2SO4, filtered and concentrated under vacuum. The crude residue was purified by silica gel chromatography eluting with 0-25% EtOAc/hexanes to give the desired product as a pale-yellow oil.

1. stirringAfter stirring for 1 hour at −30° C.
2. stirringThe suspension was stirred for a further 30 minutes at −30° C.
3. temperatureheated
4. temperatureto reflux overnight
5. temperatureto cool to room temperature
6. washwashed with water (10.0 mL)
7. dry with materialThe organic layer was dried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated under vacuum
10. customThe crude residue was purified by silica gel chromatography
11. washeluting with 0-25% EtOAc/hexanes