反应详情

To the solution of the ester (XV) (290 mg, 0.51 mmol) in MeOH (10 mL) was added 4 M NaOH dropwise until pH=13. The mixture was stirred overnight at room temperature before evaporating the MeOH under reduced pressure. The residue was mixed with water and washed with ether. After acidifying to pH˜3 with 2 M HCl, the product was extracted with DCM, dried over MgSO4 and concentrated under vacuum to give (S)-5-(bis(2-(tert-butoxycarbonylamino)ethyl)amino)-2-(tert-butoxycarbonylamino)-5-oxopentanoic acid (XVI) (250 mg, 0.45 mmol, 88% yield). ESIMS found for C24H44N4O9 m/z 533 (M+H).

1. custombefore evaporating the MeOH under reduced pressure
2. additionThe residue was mixed with water
3. washwashed with ether
4. extractionthe product was extracted with DCM
5. dry with materialdried over MgSO4
6. concentrationconcentrated under vacuum