反应 #1884976

反应方程式

lithium hydroxide

methanol

1-(2(S)-tert-Butoxycarbonylamino-non-8-enoyl)-4(R)-hydroxy-pyrrolidine-2(S)-carboxylic acid methyl ester

water

→

1-(2(S)-tert-butoxycarbonylamino-8-nonenoyl)-4(R)-hydroxy-pyrrolidine-2(S)-carboxylic acid

收率 96.1%

溶剂

THF

反应条件

后处理

1. 1
   浓缩concentrated in vacuo
2. 2
   workup.ADDITIONthe aqueous phase was treated with 1N HCl until the pH was 4
3. 3
   萃取This acidic solution was extracted with EtOAc (3×)
4. 4
   干燥The combined EtOAc extracts were dried (MgSO4)
5. 5
   浓缩concentrated in vacuo

实验过程

1-(2(S)-tert-Butoxycarbonylamino-non-8-enoyl)-4(R)-hydroxy-pyrrolidine-2(S)-carboxylic acid methyl ester (4.7 g, 11.8 mmol) was dissolved in THF (80 mL), methanol (20 mL), and water (40 mL). Powdered lithium hydroxide (5.6 g, 233 mmol) was added. The light yellow slurry was stirred at rt under N2 for 16 h, and then concentrated in vacuo. The residue was partioned between ether and water. The ether phase was discarded, and the aqueous phase was treated with 1N HCl until the pH was 4. This acidic solution was extracted with EtOAc (3×). The combined EtOAc extracts were dried (MgSO4) and concentrated in vacuo to give 4.36 g (96%) of 1-(2(S)-tert-butoxycarbonylamino-8-nonenoyl)-4(R)-hydroxy-pyrrolidine-2(S)-carboxylic acid as a white solid. This acid was then dissolved in 150 mL of DMF and (1R,2S)-1-amino-2-vinylcyclopropane carboxylic acid ethyl ester hydrochloride (2.61 g, 13.6 mmol), N-methyl morpholine (2.5 mL, 22.6 mmol), and HATU (5.2 g, 13.7 mmol) was added. The reaction mixture was stirred at rt under N2 for 16 h, and then concentrated in vacuo. The residue was partitioned between ethyl acetate and pH 4 buffer (biphthalate). The organic phase was washed with sat. aq. NaHCO3, dried (MgSO4), and concentrated in vacuo to give the crude product. Flash chromatography (60%-80% ethyl acetate/hexane) gave 6.0 g (98%) of 1-{[1-(2(S)-tert-Butoxycarbonylamino-non-8-enoyl)-4(R)-hydroxy-pyrrolidine-2(carbonyl]-(1R)-amino}-2(S)-vinyl-cyclopropanecarboxylic acid ethyl ester as a white solid: 1H NMR (500 MHz, CD3OD) δ 1.25 (t, J=7.2 Hz, 3 H), 1.33-1.80 (m, 10 H), 1.46 (s, 9 H), 2.09 (m, 3 H), 2.25 (m, 2 H), 3.76 (m, 2 H), 4.14 (m, 2 H), 4.27 (dd, J=8.5, 5.2 Hz, 1 H), 4.50 (m, 2 H), 4.94 (d, J=10.1 Hz, 1 H), 5.01 (dd, J=17.1, 1.8 Hz, 1 H), 5.11 (dd, J=10.4, 1.8 Hz, 1 H), 5.30 (d, J=15.6 Hz, 1 H), 5.80 (m, 2 H), 8.57 (s, 1 H); MS m/z 522 (M++1).

来源