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Crystal structure of N-(tert-but-oxy-carbon-yl)glycyl-(Z)-β-bromo-dehydro-alanine methyl ester [Boc-Gly-(β-Br)((Z))ΔAla-OMe].

Lenartowicz P, Makowski M, Zarychta B, Ejsmont K - Acta Crystallogr Sect E Struct Rep Online (2014)

Bottom Line: The dipeptide folding is influenced by an inter-molecular N-H⋯O hydrogen bond and also minimizes steric repulsion.In the crystal, mol-ecules are linked by strong N-H⋯O hydrogen bonds, generating (001) sheets.The sheets are linked by weak C-H⋯O and C-H⋯Br bonds and short Br⋯Br [3.4149 (3) Å] inter-actions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland.

ABSTRACT
The title compound, C11H17BrN2O5, is a de-hydro-amino acid with a C=C bond between the α- and β-C atoms. The amino acid residues are linked trans to each other and there are no strong intra-molecular hydrogen bonds. The torsion angles indicate a non-helical conformation of the mol-ecule. The dipeptide folding is influenced by an inter-molecular N-H⋯O hydrogen bond and also minimizes steric repulsion. In the crystal, mol-ecules are linked by strong N-H⋯O hydrogen bonds, generating (001) sheets. The sheets are linked by weak C-H⋯O and C-H⋯Br bonds and short Br⋯Br [3.4149 (3) Å] inter-actions.

No MeSH data available.


Related in: MedlinePlus

The mol­ecular structure of Boc–Gly–(β-Br)(Z)ΔAla–OMe along with selected intra­molecular hydrogen bonds (dashed lines), drawn with 50% displacement ellipsoids.
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fig1: The mol­ecular structure of Boc–Gly–(β-Br)(Z)ΔAla–OMe along with selected intra­molecular hydrogen bonds (dashed lines), drawn with 50% displacement ellipsoids.

Mentions: The mol­ecular structure of the title compound, (I), is shown in Fig. 1 ▶. The amino acids in the compound are linked trans to each other. The ω2 angle (C9—C10—N12—C13) is 175.79 (16)°, while ω3 (O5—C6—N8—C9) is 176.12 (15)°. There are no strong intra­molecular hydrogen bonds. The values of the ϕ2,3 and ψ2,3 angles corresponds to a non-helical conformation (Venkatachalam, 1968 ▶). The dipeptide folds accordingly to the inter­molecular N—H⋯O-type hydrogen bonds. The β-bromo-de­hydro­alanine moiety shows typical geometrical tendencies. The C10—N12 bond is longer [1.366 (2) Å] than a typical bond in alanine, while the N12—C13 bond is shorter [1.406 (2) Å]. This effect is common for other de­hydro-residues (Ajó et al., 1979 ▶; Pieroni et al. 1975 ▶; Rzeszotarska et al., 2002 ▶; Jain & Chauhan, 1996 ▶). This indicates conjugation between the side chain of de­hydro­alanine and the peptide bond. The torsion angles around the Br(H)C=C grouping are −0.9 (3) and −174.28 (13)° (N12—C13—C14—Br15 and C16—C13—C14—Br15, respectively), meaning the stereochemistry about the bond is especially planar. This is consistent with the nature of an sp2-hybridized carbon on C13. The valance angles around the de­hydro­alanine group show some unusual values, especially N12—C13—C14 [124.27 (18)°], which may correspond to the presence of the bromine atom in the structure. The other angles are normal, as the backbone of the mol­ecule is folded to minimize steric repulsion. The Boc group features two short intra­molecular C—H⋯O contacts


Crystal structure of N-(tert-but-oxy-carbon-yl)glycyl-(Z)-β-bromo-dehydro-alanine methyl ester [Boc-Gly-(β-Br)((Z))ΔAla-OMe].

Lenartowicz P, Makowski M, Zarychta B, Ejsmont K - Acta Crystallogr Sect E Struct Rep Online (2014)

The mol­ecular structure of Boc–Gly–(β-Br)(Z)ΔAla–OMe along with selected intra­molecular hydrogen bonds (dashed lines), drawn with 50% displacement ellipsoids.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257433&req=5

fig1: The mol­ecular structure of Boc–Gly–(β-Br)(Z)ΔAla–OMe along with selected intra­molecular hydrogen bonds (dashed lines), drawn with 50% displacement ellipsoids.
Mentions: The mol­ecular structure of the title compound, (I), is shown in Fig. 1 ▶. The amino acids in the compound are linked trans to each other. The ω2 angle (C9—C10—N12—C13) is 175.79 (16)°, while ω3 (O5—C6—N8—C9) is 176.12 (15)°. There are no strong intra­molecular hydrogen bonds. The values of the ϕ2,3 and ψ2,3 angles corresponds to a non-helical conformation (Venkatachalam, 1968 ▶). The dipeptide folds accordingly to the inter­molecular N—H⋯O-type hydrogen bonds. The β-bromo-de­hydro­alanine moiety shows typical geometrical tendencies. The C10—N12 bond is longer [1.366 (2) Å] than a typical bond in alanine, while the N12—C13 bond is shorter [1.406 (2) Å]. This effect is common for other de­hydro-residues (Ajó et al., 1979 ▶; Pieroni et al. 1975 ▶; Rzeszotarska et al., 2002 ▶; Jain & Chauhan, 1996 ▶). This indicates conjugation between the side chain of de­hydro­alanine and the peptide bond. The torsion angles around the Br(H)C=C grouping are −0.9 (3) and −174.28 (13)° (N12—C13—C14—Br15 and C16—C13—C14—Br15, respectively), meaning the stereochemistry about the bond is especially planar. This is consistent with the nature of an sp2-hybridized carbon on C13. The valance angles around the de­hydro­alanine group show some unusual values, especially N12—C13—C14 [124.27 (18)°], which may correspond to the presence of the bromine atom in the structure. The other angles are normal, as the backbone of the mol­ecule is folded to minimize steric repulsion. The Boc group features two short intra­molecular C—H⋯O contacts

Bottom Line: The dipeptide folding is influenced by an inter-molecular N-H⋯O hydrogen bond and also minimizes steric repulsion.In the crystal, mol-ecules are linked by strong N-H⋯O hydrogen bonds, generating (001) sheets.The sheets are linked by weak C-H⋯O and C-H⋯Br bonds and short Br⋯Br [3.4149 (3) Å] inter-actions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland.

ABSTRACT
The title compound, C11H17BrN2O5, is a de-hydro-amino acid with a C=C bond between the α- and β-C atoms. The amino acid residues are linked trans to each other and there are no strong intra-molecular hydrogen bonds. The torsion angles indicate a non-helical conformation of the mol-ecule. The dipeptide folding is influenced by an inter-molecular N-H⋯O hydrogen bond and also minimizes steric repulsion. In the crystal, mol-ecules are linked by strong N-H⋯O hydrogen bonds, generating (001) sheets. The sheets are linked by weak C-H⋯O and C-H⋯Br bonds and short Br⋯Br [3.4149 (3) Å] inter-actions.

No MeSH data available.


Related in: MedlinePlus