反应详情

1.6 g of ethyl 2-(diethylphosphoryl)-2-isopropylacetate was dissolved in 30 ml tetrahydrofuran, and 0.24 g of 60% sodium hydride was added thereto under ice-cooling. After stirring the reaction solution for 30 minutes under ice-cooling, 1.2 g of tert-butyl 5-formyl-2-methoxybenzoate was added, followed by stirring at room temperature for 3 hours. Aqueous ammonium chloride solution was added to the reaction mixture, followed by extracting with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and the solvent was evaporated. The residue was subjected to silica gel column chromatography, and from fractions eluted with hexane-ethyl acetate (3:1), 1.5 g of tert-butyl 5-(3-ethoxy-2-isopropoxy-3-oxo-1-propenyl)-2-methoxybenzoate was obtained as an E-Z mixture.

1. temperatureunder ice-cooling
2. temperaturecooling
3. stirringby stirring at room temperature for 3 hours
4. extractionby extracting with ethyl acetate
5. washThe organic layer was washed with brine
6. dry with materialdried over anhydrous magnesium sulfate
7. customthe solvent was evaporated
8. washfrom fractions eluted with hexane-ethyl acetate (3:1)