Ethyl (1R,2S)-1-[[(1,1-dimethylethoxy)carbonyl]amino]-2-ethenylcyclopropanecarboxylate → Cyclopropanecarboxylic acid, 1-amino-2-ethenyl-, ethyl ester, hydrochloride (1:1), (1R,2S)-

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Reaction Steps

Ethyl 1(R)-tert-butoxycarbonylamino-2(S)-vinylcyclopropanecarboxylate (8.5 g, 33.3 mmol) was stirred under an N2 atmosphere with 200 mL of 4N HCl/dioxane (Aldrich) at rt for 3 h. The solvent was removed under reduced pressure keeping the temperature below 40 C. This gave 6.57 g (˜100%) of ethyl 1(R)-amino-2(S)-vinylcyclopropanecarboxylate hydrochloride as a light tan solid. 1H NMR (300 MHz, CD3OD) δ 1.31 (t, J=7.0Hz, 3H), 1.69-1.82 (m, 2H), 2.38 (q, J=8.8Hz, 1H), 4.29 (q, J=7.0Hz, 2H), 5.22 (d, J=10.3Hz, 1H), 5.40 (d, J=17.2Hz, 1H), 5.69-5.81 (m, 1H). MS m/z 156 (M++1).

Provenance & Evidence