title: Crystal structure of Boc-(S)-ABOC-(S)-Ala-(S)-ABOC-(S)-Phe-OBn chloro-form monosolvate.
abstract: In the title compound, phenyl (S)-2-[(S)-(1-{2-[(S)-(1-{[(tert-but-oxy)carbon-yl]amino}-bicyclo-[2.2.2]octan-2-yl)formamido]-propanamido}-bicyclo-[2.2.2]octan-2-yl)formamido]-3-phenyl-propano-ate chloro-form monosolvate, C42H56N4O7·CHCl3, the α,β-hybrid peptide contains two non-proteinogenic amino acid residues of (S)-1-amino-bicyclo-[2.2.2]octane-2-carb-oxy-lic acid [(S)-ABOC], two amino acid residues of (S)-2-amino-propanoic acid [(S)-Ala] and (S)-2-amino-3-phenyl-propanoic acid [(S)-Phe], and protecting groups of tert-but-oxy-carbonyl (Boc) and benzyl ester (OBn). The tetra-mer folds into a right-handed mixed 11/9 helix stabilized by intra-molecular i,i + 3 and i,i - 1 C=O⋯H-N hydrogen bonds. In the crystal, the oligomers are linked by N-H⋯O=C hydrogen bonds into chains along the a-axis direction. The chloro-form solvent mol-ecules are inter-calated between the folded chains via C-H⋯O=C inter-actions.
authors.affiliation: Université de Lorraine, UMR 7036 CRM2, Vandoeuvre-lès-Nancy, France ; CNRS, UMR 7036 CRM2, Vandoeuvre-lès-Nancy, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Wenger
authors.affiliation: IBMM, UMR 5247 CNRS-Université Montpellier-ENSCM, 15 avenue Charles Flahault, 34093 Montpellier Cedex 5, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Moulat
authors.affiliation: IBMM, UMR 5247 CNRS-Université Montpellier-ENSCM, 15 avenue Charles Flahault, 34093 Montpellier Cedex 5, France.
authors.forename: Baptiste
authors.initials: B
authors.lastname: Legrand
authors.affiliation: IBMM, UMR 5247 CNRS-Université Montpellier-ENSCM, 15 avenue Charles Flahault, 34093 Montpellier Cedex 5, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Amblard
authors.affiliation: IBMM, UMR 5247 CNRS-Université Montpellier-ENSCM, 15 avenue Charles Flahault, 34093 Montpellier Cedex 5, France.
authors.forename: Monique
authors.initials: M
authors.lastname: Calmès
authors.affiliation: Université de Lorraine, UMR 7036 CRM2, Vandoeuvre-lès-Nancy, France ; CNRS, UMR 7036 CRM2, Vandoeuvre-lès-Nancy, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Didierjean
keywords: (S)-1-amino­bicyclo­[2.2.2]octane-2-carb­oxy­lic acid; (S)-ABOC; (S)-Ala; (S)-Phe; 11/9 helix; Boc; OBn; crystal structure; hydrogen bonding; α,β-hybrid peptide