Carbamate → (1S,2S)-1-Amino-2-ethylcyclopropanecarboxylic acid

To carbamate 14c (267 mg, 0.810 mmol) was added a 1.0 M TBAF solution in THF (1.62 mL, 1.62 mmol, 2.0 eq.). The reaction mixture was stirred overnight at RT, refluxed for 30 min and then diluted with AcOEt. The solution was successively washed with water (2×) and brine. After the usual treatment (MgSO4, filtration and concentration) the desired amine 14d was isolated (122 mg, 0.721 mmol, 89% yield) as a pale yellow liquid. 1H NMR (CDCl3) δ5.94-5.86 (m,1H), 5.31-5.22 (m, 2H), 4.58 (d, J=5.7 Hz, 2H), 1.75 (bs, 2H), 1.61-1.53 (m, 2H), 1.51-1.42 (m, 2H), 1.00 (t, J=7.3 Hz, 3H), 0.70-0.62 (m, 1H).