반응 #640626

반응 방정식

Lithium hydroxide monohydrate

Ethyl (1R,2R)-1-(tert-butoxycarbonylamino)-2-vinyl-cyclopropane-1-carboxylate

water

tetrahydrofuran

→

title compound

수율 96.5%

(1R,2R)-1-(tert-butoxycarbonylamino)-2-vinyl-cyclopropane-1-carboxylic acid

수율 96.5%

용매

—

ice water

ethyl acetate

반응 조건

후처리

1. 1
   기타consumption of the starting material
2. 2
   workup.WAITThe reaction mixture was left
3. 3
   온도to cool down to ambient temperature
4. 4
   workup.ADDITIONdiluted with ethyl acetate (50 mL)
5. 5
   세척the aqueous phase washed further with ethyl acetate (50 mL)
6. 6
   workup.ADDITIONThe aqueous phase was acidified to pH 3 by slow addition of 1M hydrochloric acid
7. 7
   추출then extracted with ethyl acetate (2×80 mL)
8. 8
   세척washed with brine (50 mL)
9. 9
   건조dried over sodium sulphate
10. 10
    여과filtered
11. 11
    농축concentrated to dryness

실험 절차

Ethyl (1R,2R)-1-(tert-butoxycarbonylamino)-2-vinyl-cyclopropane-1-carboxylate (2.0 g, 7.84 mmol., 1.0 eq.), water (60 mL) and tetrahydrofuran (50 mL) were charged into a 250 mL round bottom flask placed in ice/water bath. Lithium hydroxide monohydrate (0.523 g, 12.94 mmol., 1.65 eq.) was added portion wise and the reaction mixture heated at 80° C. for 15 hours. TLC analysis of the reaction mixture (heptanes:ethyl acetate, 1:1) showed full consumption of the starting material. The reaction mixture was left to cool down to ambient temperature and diluted with ethyl acetate (50 mL). The organic phase was discarded, and the aqueous phase washed further with ethyl acetate (50 mL). The aqueous phase was acidified to pH 3 by slow addition of 1M hydrochloric acid then extracted with ethyl acetate (2×80 mL). The organic extracts were pooled, washed with brine (50 mL), dried over sodium sulphate, filtered and concentrated to dryness to give 1.72 g (96%) of the title compound as a pale yellow solid. 1H NMR (500 MHz, CDCl3) δ ppm 5.67-5.86 (m, 1 H), 5.31 (d, J=17.10 Hz, 1 H), 5.18-5.28 (m, 1 H), 5.15 (d, J=10.32 Hz, 1 H), 2.20 (q, J=8.86 Hz, 1 H), 1.70-1.92 (m, 1 H), 1.50-1.65 (m, 1 H), 1.46 (s, 9 H). LC-MS: purity 100% (ELS), tR 1.56 min, m/z [M−H]-226.10.

출처