Réaction #632016

Équation de réaction

1(R)-tert-butoxycarbonylamino-2(S)-vinyl-cyclopropanecarboxylic acid ethyl ester

LiOH

→

desired compound

Rendement 87.3%

1(R)-tert-butoxycarbonylamino-2(S)-vinyl-cyclopropanecarboxylic acid

Rendement 87.3%

Solvants

THF

methanol

water

Conditions de réaction

Traitement

1. 1
   Autrequenched with 1N NaOH (15 mL) and water (20 mL)
2. 2
   LavageThe resulting mixture was washed with ethyl acetate (20 mL)
3. 3
   Extractionthe organic phase was extracted with 20 mL 0.5N NaOH
4. 4
   Extractionextracted with ethyl acetate (3×40 mL)
5. 5
   LavageThe combined organic extracts were washed with brine
6. 6
   Séchagedried (MgSO4)
7. 7
   Filtrationfiltered
8. 8
   Concentrationconcentrated

Mode opératoire

To a solution of 1(R)-tert-butoxycarbonylamino-2(S)-vinyl-cyclopropanecarboxylic acid ethyl ester (3.28 g, 13.2 mmol) in THF (7 mL) and methanol (7 mL) was added a suspension of LiOH (1.27 g, 53.0 mmol) in water (14 mL). The mixture was stirred overnight at room temperature and quenched with 1N NaOH (15 mL) and water (20 mL). The resulting mixture was washed with ethyl acetate (20 mL), and the organic phase was extracted with 20 mL 0.5N NaOH. The combined aqueous phases were acidified with 1N HCl to pH 4 and extracted with ethyl acetate (3×40 mL). The combined organic extracts were washed with brine, dried (MgSO4), filtered and concentrated to provide the desired compound as a white solid (2.62 g, 87%). 1HNMR: (DMSO-d6) δ 1.22-1.26 (m, 1H), 1.37 (s, 9H), 1.50-1.52 (m, 1H), 2.05 (q, J=9 Hz, 1H), 5.04 (d, J=10 Hz, 1H), 5.22 (d, J=17 Hz, 1H), 5.64-5.71 (m, 1H), 7.18, 7.53 (s, NH (rotamers), 12.4 (br s, 1H)); LC-MS (retention time: 1.67 minutes, method B), MS m/z 228 (M++H).

Source