反应详情

温度

-70 °C

8 ml of a methylene chloride solution containing 0.81 g (6.4 mmol) of oxalyl chloride was cooled to −70° C., and 2 ml of a methylene chloride solution containing 0.65 g of DMSO was added dropwise over 10 minutes. The mixture was stirred at −60° C. for 10 minutes, and then, 5 ml of a methylene chloride solution containing 1.01 g (3.27 mmol) of benzyl 3-t-butoxycarbonylamino-4-hydroxybutanoate was added dropwise over 10 minutes. The mixture was stirred at −50° C. for one hour, and then, 3.3 ml of triethylamine was added dropwise. After completion of the dropwise addition, the temperature of the mixture was gradually raised and when the temperature reached to 0° C., a saturated aqueous ammonium chloride solution was added to the mixture and the resulting mixture was extracted with ethyl acetate. The organic layer was washed with a saturated aqueous saline solution and dried over anhydrous sodium sulfate. The organic layer was concentrated under reduced pressure, and the residue was purified by the silica gel column chromatography method (n-hexane/ethyl acetate=7/3) to obtain 0.80 g (2.6 mmol) of benzyl 3-t-butoxycarbonylamino-3-formylpropionate as pale yellowish oily product.

1. additionwas added dropwise over 10 minutes
2. additionwas added dropwise over 10 minutes
3. stirringThe mixture was stirred at −50° C. for one hour
4. additionAfter completion of the dropwise addition
5. temperaturethe temperature of the mixture was gradually raised
6. customreached to 0° C.
7. extractionthe resulting mixture was extracted with ethyl acetate
8. washThe organic layer was washed with a saturated aqueous saline solution
9. dry with materialdried over anhydrous sodium sulfate
10. concentrationThe organic layer was concentrated under reduced pressure
11. customthe residue was purified by the silica gel column chromatography method (n-hexane/ethyl acetate=7/3)