Reaktion #632016

Reaktionsgleichung

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

LiOH

→

desired compound

Ausbeute 87.3%

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

Ausbeute 87.3%

Lösungsmittel

THF

methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched with 1N NaOH (15 mL) and water (20 mL)
2. 2
   WaschenThe resulting mixture was washed with ethyl acetate (20 mL)
3. 3
   Extraktionthe organic phase was extracted with 20 mL 0.5N NaOH
4. 4
   Extraktionextracted with ethyl acetate (3×40 mL)
5. 5
   WaschenThe combined organic extracts were washed with brine
6. 6
   Trocknendried (MgSO4)
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated

Vorschrift

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).

Quelle