反应详情

To a solution of tetrahydrofurfuryl alcohol (25 g), methyl 4-hydroxybenzoate (38 g), and triphenylphosphine (72 g) in tetrahydrofuran (300 mL) was slowly added dropwise a solution of diethyl azodicarboxylate in toluene (136 mL, 40% toluene solution) at 0° C., and the mixture was stirred at room temperature for 2 hr. The reaction solution was concentrated, and triphenylphosphine oxide was precipitated from ethyl acetate-hexane. Triphenylphosphine oxide was removed by filtration with a glass filter, and the mother liquor was concentrated. The residue was purified by silica gel column chromatography [developing solvent; hexane:ethyl acetate=100:0 (volume ratio)→hexane:ethyl acetate=70:10 (volume ratio)] to give a colorless oil. The obtained colorless oil was dissolved in tetrahydrofuran (200 mL) and methanol (100 mL), 8N aqueous sodium hydroxide solution (100 mL) was added, and the mixture was stirred at 80° C. for 2 hr with heating. The reaction solution was concentrated, cooled to 0° C., neutralized with 6N hydrochloric acid, and extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give the title compound (17 g, yield 31%) as colorless crystals.

1. concentrationThe reaction solution was concentrated
2. customtriphenylphosphine oxide was precipitated from ethyl acetate-hexane
3. customTriphenylphosphine oxide was removed by filtration with a glass
4. filtrationfilter
5. concentrationthe mother liquor was concentrated
6. customThe residue was purified by silica gel column chromatography [developing solvent; hexane:ethyl acetate=100:0 (volume ratio)→hexane:ethyl acetate=70:10 (volume ratio)]
7. customto give a colorless oil
8. stirringthe mixture was stirred at 80° C. for 2 hr
9. temperaturewith heating
10. concentrationThe reaction solution was concentrated
11. temperaturecooled to 0° C.
12. extractionextracted with ethyl acetate
13. washThe organic layer was washed with saturated brine
14. dry with materialdried over anhydrous magnesium sulfate
15. customthe solvent was evaporated under reduced pressure