反应详情

To a solution of (S)-2-tert-butoxycarbonylamino-3-cyclohexyl-propionic acid (5 g, 19.4 mmol) in DMF (50 mL) at 0° C. was added cyclopentanol (8.8 ml, 97.15 mmol), EDC (4.09 g, 21.37 mmol) and finally DMAP (237 mg, 1.94 mmol). The reaction mixture was warmed to RT and stirred for 18 h. The DMF was removed in vacuo to give a clear oil. This was separated between water and EtOAc. The organic phase was dried (MgSO4) and concentrated in vacuo. The crude extract was purified by column chromatography (25% EtOAC in heptane) to yield the desired product as a clear oil (14.87 g, 55%). 1H NMR (300 MHz, d6-DMSO) δ: 7.09 (1H, d), 5.08 (1H, t), 3.76 (1H, t), 1.50-1.85 (10H, br m), 1.39 (9H, s), 1.00-1.25 (9H, br m).

1. customThe DMF was removed in vacuo
2. customto give a clear oil
3. customThis was separated between water and EtOAc
4. dry with materialThe organic phase was dried (MgSO4)
5. concentrationconcentrated in vacuo
6. extractionThe crude extract
7. customwas purified by column chromatography (25% EtOAC in heptane)