Acta Cryst. (2003). E59, o1581-o1583  [ doi:10.1107/S1600536803020889 ]

N-HO=C hydrogen bonding and OO=C repulsive interactions in tert-butoxycarbonyl-L-leucyl-L-alanine ethyl ester (Boc-L-Leu-L-Ala-OEt)

H. Oku, K. Yamada and R. Katakai

Abstract: The crystal structure of the title compound, C₁₆H₃₀N₂O₅, has been determined. In the asymmetric unit, there are three independent molecules which adopt extended -sheet conformations. These molecules are linked together into an infinite column by six hydrogen bonds of the type -NHO=C. All the ester C=O groups are perpendicular to the column axis. This orientation probably reflects a repulsive force between two electronegative O atoms, viz. OO=C.

Online 30 September 2003

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