反应详情

A solution of NaOH (0.3 M, 1.6 mL, 0.49 mmol) was added to 3-cyclopentyl-5-(3-furan-2-yl-propionylamino)-3-hydroxy-pentanoic acid ethyl ester (86 mg, 0.245 mmol) from Step 1 below and stirred at room temperature until complete by HPLC. The reaction was diluted with 10 mL CH2Cl2, and washed with 10 mL saturated NH4Cl. The aqueous layer was extracted with 2×10 mL CH2Cl2, and the organic layers were combined. After concentrating by rotary evaporation, the residue was purified by flash chromatography to give the desired compound (29 mg, 37% yield). 1H NMR (CDCl3) δ: 1.39-1.75 (m, 8H), 2.00-2.09 (m, 2H), 2.39-2.52 (m, 5H), 2.90 (t, J=7.45 Hz, 2H), 3.29-3.40 (m, 2H), 5.96 (s, 1H), 6.2 (s, 1H), 6.31 (br, 1H), 7.23 (s, 1H). MS (ESI): 322 (M−H).

1. washwashed with 10 mL saturated NH4Cl
2. extractionThe aqueous layer was extracted with 2×10 mL CH2Cl2
3. concentrationAfter concentrating by rotary evaporation
4. customthe residue was purified by flash chromatography