反应详情

To a suspension of (furan-2-yl)methyl triphenylphosphonium bromide (4.04 g, 9.54 mmol) obtained in Reference example 1 in tetrahydrofuran (32.4 ml) was added potassium t-butoxide (1.06 g, 9.45 mmol) with stirring under ice-cooling, and the resulting mixture was furthermore stirred under ice-cooling for 15 minutes. After stirring, to the reaction mixture was added a solution of (2S)-2-t-butoxycarbonylamino-2-ethyl-3-n-hexanoyloxy-1-propanal (2.01 g, 6.37 mmol) obtained in Reference example (14b) in tetrahydrofuran (10 ml) with stirring under ice-cooling over a 5-minute interval, and the resulting mixture was furthermore stirred under ice-cooling for 30 minutes. After stirring, saturated aqueous ammonium chloride solution was added to the reaction mixture to quench the reaction, and the reaction temperature was raised to room temperature. After evaporation of the reaction mixture in vacuo, ethyl acetate and water were added to the residue, and the resulting mixture was extracted with ethyl acetate. The extract was washed with saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. After filtration, the solvent was removed in vacuo, and the residue was purified by chromatography on a silica gel column using a mixed solvent of hexane and ethyl acetate (5:1) as the eluent to afford the title compound (2.385 g, yield: 99%)

1. temperaturecooling
2. stirringthe resulting mixture was furthermore stirred under ice-
3. temperaturecooling for 15 minutes
4. stirringAfter stirring, to the reaction mixture
5. stirringwith stirring under ice-
6. temperaturecooling over a 5-minute interval
7. stirringthe resulting mixture was furthermore stirred under ice-
8. temperaturecooling for 30 minutes
9. stirringAfter stirring
10. customto quench
11. customthe reaction
12. customAfter evaporation of the reaction mixture in vacuo, ethyl acetate and water
13. additionwere added to the residue
14. extractionthe resulting mixture was extracted with ethyl acetate
15. washThe extract was washed with saturated aqueous sodium chloride solution
16. dry with materialdried over anhydrous sodium sulfate
17. filtrationAfter filtration
18. customthe solvent was removed in vacuo
19. customthe residue was purified by chromatography on a silica gel column