反应详情

温度

-78 °C

To a solution of ethyl 3-(2-bromo-3,4,5,6-tetramethoxyphenyl)-2-ethoxycarbonyl-2-[3-(4-ethoxycarbonylphenoxy)propyl]propionate (40.0 g) in THF (400 ml) was dropwise added n-butyl lithium in hexane (1.68M; 41.8 ml) under nitrogen atmosphere at −100° C. or under and the solution was allowed to warm to −78° C. in 30 min. The reaction mixture was cooled to −100° C. again and a solution of acetic acid (7.33 g) in THF (20 ml) was dropwise added, which was then allowed to warm to room temperature. The reaction mixture was diluted with ethyl acetate and the organic layer was washed with saturated aqueous sodium bicarbonate, water, and saturated aqueous sodium chloride, and dried. The solvent was removed in vacuo. The residue was purified by silica gel column chromatography (hexane to hexane:ethyl acetate=7:1) to yield the entitled compound (29.7 g) as an oil.

1. customat −100° C.
2. temperatureThe reaction mixture was cooled to −100° C. again
3. temperatureto warm to room temperature
4. washthe organic layer was washed with saturated aqueous sodium bicarbonate, water, and saturated aqueous sodium chloride
5. customdried
6. customThe solvent was removed in vacuo
7. customThe residue was purified by silica gel column chromatography (hexane to hexane:ethyl acetate=7:1)