反应详情

Into a 500-ml four-necked flask were poured 61.8 g (0.163 mole) of ethyl (3R)-5-benzyloxycarbonylamino-3-(2-tetrahydropyranyloxy)pentanoate (2-b) obtained by the above process A and 124 ml of methanol. Then, the contents of the flask were cooled with ice. Furthermore, 72 ml of a 10 wt% aqueous sodium hydroxide solution were added to the contents, and the contents were allowed to completely hydrolyze for 2 hours at the same temperature. Into the solution was added 90 ml of water, and the aqueous mixture was extracted with two 75 ml portions of butyl acetate. 125 ml of toluene and 100 ml of a 5 wt % aqueous hydrochloric acid solution were added to the aqueous layer to thereby adjust the pH to 4.5. The toluene layer was washed with a saturated sodium chloride solution and then dried with magnesium sulfate. After removing the solvent by distillation, 46.9 g (82% yield) of the intended oily product was obtained.

1. temperatureThen, the contents of the flask were cooled with ice
2. extractionthe aqueous mixture was extracted with two 75 ml portions of butyl acetate
3. addition125 ml of toluene and 100 ml of a 5 wt % aqueous hydrochloric acid solution were added to the aqueous layer
4. washThe toluene layer was washed with a saturated sodium chloride solution
5. dry with materialdried with magnesium sulfate
6. customAfter removing the solvent
7. distillationby distillation