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

N-BOC-(1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid ethyl ester (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 (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid ethyl ester hydrochloride as a light tan solid. 1H NMR (300 MHz, CD3OD) δ 1.31 (t, J=7.0 Hz, 3H), 1.69–1.82 (m, 2H), 2.38 (q, J=8.8 Hz, 1H), 4.29 (q, J=7.0 Hz, 2H), 5.22 (d, J=10.3 Hz, 1H), 5.40 (d, J=17.2 Hz, 1H), 5.69–5.81 (m, 1H). LC-MS (Method A, retention time: 0.58 min), MS m/z 156 (M++1).

Provenance & Evidence