A solution of (S)-2-(tert-butoxycarbonylamino)propyl methanesulfonate (2.0 g, 7.9 mmol) in dioxane (10 ml) was acidified with an aqueous solution of HCl (10 ml, 4 M) and was stirred for 1 h. The volatiles were removed under reduced pressure and the residue was washed with acetonitrile. Yield 0.84 g (56%).

¹H NMR (400 MHz, 298 K, MeOD) δ_H 4.44 (1H, dd, ³J_HH = 11.2 Hz, ²J_HH = 3.4 Hz, CH₂), 4.27 (1H, dd, ³J_HH = 11.2 Hz, ²J_HH = 6.8 Hz, CH₂), 3.73 – 3.62 (1H, m, CH), 3.19 (3H, s, SO₃CH₃), 1.37 (3H, d, ³J_HH = 6.8 Hz, CHCH₃).

¹³C NMR (100 MHz, 298 K, MeOD) δ_C 70.65 (CH₂), 47.93 (CH), 37.40 (SO₃CH₃), 15.06 (CH₃).

MS (ESI⁺) m/z 154.2 ([M-Cl]⁺)

IR (cm^-1) ν 2865, 2779, 2713, 2693, 2604, 2525, 2022, 1609, 1508, 1460, 1403, 1387, 1324, 1282, 1211, 1170, 1134, 1022, 998, 967, 947, 928, 852, 819, 769.

K. Higashiura, H. Morino, H. Matsuura, Y. Toyomaki and K. Ienaga, J. Chem. Soc., Perkin Trans. 1, 1989, 1479-1481.http://dx.doi.org/10.1039/p19890001479