反应详情

温度

-15 °C

Ethyl 4-(S)-benzyloxycarbonylamino-4-cyclopropyl-3-hydroxybutanoate (1.488 g, 4.630 mmol) was dissolved in dry dichloromethane (50 ml) and stirred at -15° C. while adding triethylamine (1,291 μl, 9.260 mmol), and then methanesulfonyl chloride (449 μl, 5.80 mmol) was added dropwise thereto and the mixture was stirred at the same temperature for 1 hour. 1,8-Diazabicyclo[5.4.0]-7-undecene (1,486 μl, 1.955 mmol) was added dropwise to the reaction solution, and the mixture was gradually warmed up to room temperature and then stirred for 15 hours. The reaction solution was washed with 10% citric acid aqueous solution (50 ml), and the organic layer was separated and then the aqueous layer was extracted with chloroform (30 ml). The organic layers were combined, washed with water (50 ml) and saturated sodium chloride aqueous solution (50 ml) in that order, and then dried over anhydrous magnesium sulfate. After filtration, the solvent was evaporated under a reduced pressure, and the thus obtained residue was applied to a flash silica gel chromatography and eluted with n-hexane:ethyl acetate=4:1, thereby obtaining 1.174 g (87.2%) of the title compound as a light yellow oil.

1. stirringthe mixture was stirred at the same temperature for 1 hour
2. temperaturethe mixture was gradually warmed up to room temperature
3. stirringstirred for 15 hours
4. washThe reaction solution was washed with 10% citric acid aqueous solution (50 ml)
5. customthe organic layer was separated
6. extractionthe aqueous layer was extracted with chloroform (30 ml)
7. washwashed with water (50 ml) and saturated sodium chloride aqueous solution (50 ml) in that order
8. dry with materialdried over anhydrous magnesium sulfate
9. filtrationAfter filtration
10. customthe solvent was evaporated under a reduced pressure
11. washeluted with n-hexane