Acta Cryst. (2003). E59, o1130-o1132  [ doi:10.1107/S1600536803014831 ]

cis- and trans-Conformers at the urethane linkage: tert-butoxycarbonyl-L-alanyl-L-proline methyl ester (Boc-L-Ala-L-Pro-OMe)

H. Oku, K. Yamada and R. Katakai

Abstract: Crystals of the title compound, C₁₆H₂₈N₂O₇, were successfully grown from an oily product at low temperature (below 260 K). There are two independent molecules in the asymmetric unit. One molecule has a cis and the other a trans conformation at the urethane linkage, -O-CO-NH-. Independent molecules are linked into dimers, but not into chains, by N-HO=C hydrogen bonds.

Online 17 July 2003

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