Lithium Hydroxide → (1R,2S)-1-(((1,1-Dimethylethoxy)carbonyl)amino)-2-ethenylcyclopropanecarboxylic acid

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 until pH 4 and extracted with ethyl acetate (3×40 mL). The combined organic extracts were washed with brine, dried (MgSO4), filtered and concentrated to yield the title compound as a white solid (2.62 g, 87%). 1H NMR: (DMSO-d6) 1.22-1.26 (m, 1H), 1.37 (s, 9H), 1.50-1.52 (m, 1H), 2.05 (q, J=9Hz, 1H), 5.04 (d, J=10Hz, 1H), 5.22 (d, J=17Hz, 1H), 5.64-5.71 (m, 1H), 7.18, 7.53 (s, NH (rotamers), 12.4 (br s, 1H)); MS m/z 228 (M++H).

1. customquenched with 1N NaOH (15 mL) and water (20 mL)
2. washThe resulting mixture was washed with ethyl acetate (20 mL)
3. extractionthe organic phase was extracted with 20 mL 0.5N NaOH
4. extractionextracted with ethyl acetate (3×40 mL)
5. washThe combined organic extracts were washed with brine
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-ee269898e30a4808a96865b1e23d23c3

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07772183B2