反应详情

50.0 g of 6-(2,4-dihydroxybenzoyl)-2-chromanone, 17.6 mL of cyclopentanol, and 55.4 g of triphenylphosphine were dissolved in 500 mL of tetrahydrofuran, to which 41.6 mL of diisopropyl azodicarboxylate was added dropwise at temperatures of 15 to 32° C., and this solution was stirred for 30 minutes at room temperature. The reaction mixture was poured into a mixture of ethyl acetate and water for the separation of the organic phase therefrom. After the resultant organic phase was washed with water and a saturated sodium chloride solution successively, the washed phase was dried over anhydrous magnesium sulfate and the solvent was distilled out thereof under reduced pressure. The resultant residue was purified by silica gel column chromatography [eluent; hexane:ethyl acetate=3:1] to yield 54.7 g of 6-[4-(cyclopentyloxy)-2-hydroxybenzoyl]-2-chromanone as light yellow solid.

1. additionwas added dropwise at temperatures of 15 to 32° C.
2. washAfter the resultant organic phase was washed with water
3. dry with materiala saturated sodium chloride solution successively, the washed phase was dried over anhydrous magnesium sulfate
4. distillationthe solvent was distilled out thereof under reduced pressure
5. customThe resultant residue was purified by silica gel column chromatography [eluent; hexane:ethyl acetate=3:1]