反应详情

To a stirred solution of methyl N-(tert-butoxycarbonyl)-3-cyclopropyl-D-alaninate (1.0 g, 4.1 mmol) in MeOH (25 mL) at 0° C. was added 1M NaOH (5.0 mL, 5.0 mmol) dropwise. After 1 h, the cold bath was removed, and the reaction followed by HPLC. After 5.5 h, the methanol was removed at reduced pressure, and the residue diluted with 15 mL water and washed with ether. The aqueous layer was acidified with cold 2M HCl and extracted with three portions of EtOAc. The combined organic layers were washed with water, brine, dried over Na2SO4 and concentrated at reduced pressure to give the title compound as a colorless oil (929 mg): 1H NMR (300 MHz, CDCl3): δ 5.10–5.22 (br d, J=6.1 Hz, 1H), 4.35–4.46 (m, 1H), 1.72 (t, J=6.2 Hz, 2H), 1.39 (s, 9H), 0.70–0.85 (m, 1H), 0.42–0.60 (m, 2H), 0.03–0.21 (m, 2H).

1. customthe cold bath was removed
2. waitAfter 5.5 h
3. customthe methanol was removed at reduced pressure
4. additionthe residue diluted with 15 mL water
5. washwashed with ether
6. extractionextracted with three portions of EtOAc
7. washThe combined organic layers were washed with water, brine
8. dry with materialdried over Na2SO4
9. concentrationconcentrated at reduced pressure