反应详情

Deoxo-fluor™ (Bis-(2-methoxy)amino sulfur trifluoride, 1.4 mL, 7.6 mmol) was added drop-wise to a solution of methyl 2-((R)-2-(tert-butoxycarbonylamino)propanamido)-3-hydroxypropanoate (2.0 g, 6.9 mmol) in CH2Cl2 (50 mL) at −20° C. The solution was stirred for 30 min and BrCCl3 (2.45 mL, 24.8 mmol) was added drop-wise. The reaction was stirred at 2-3° C., for 8 h., quenched with sat. aq. NaHCO3 solution and extracted with ethyl acetate. The organic layer was concentrated and chromatographed on silica gel (30% ethyl acetate/70% hexanes) to yield 65% of (R)-methyl 2-(1-(tert-butoxycarbonylamino)ethyl)oxazole-4-carboxylate.

1. stirringThe reaction was stirred at 2-3° C., for 8 h.
2. customquenched with sat. aq. NaHCO3 solution
3. extractionextracted with ethyl acetate
4. concentrationThe organic layer was concentrated
5. customchromatographed on silica gel (30% ethyl acetate/70% hexanes)