title: Precursor of a beta-lactamase inhibitor: allyl (4S,8S,9R)-10-[(E)-ethylidene]-4-methoxy-11-oxo-1-azatricyclo[7.2.0.0(3,8)]undec-2-ene-2-carboxylate.
abstract: The molecular structure of the title tricyclic compound, C(17)H(21)NO(4), which is the immediate precursor of a potent synthetic inhibitor [Lek157: sodium (8S,9R)-10-[(E)-ethylidene]-4-methoxy-11-oxo-1-azatricyclo[7.2.0.0(3,8)]undec-2-ene-2-carboxylate] with remarkable potency, provides experimental evidence for the previously modelled relative position of the fused cyclohexyl ring and the carbonyl group of the beta-lactam ring, which takes part in the formation of the initial tetrahedral acyl-enzyme complex. In this hydrophobic molecule, the overall geometry is influenced by C[bond]H...O intramolecular hydrogen bonds [3.046 (4) and 3.538 (6) A, with corresponding normalized H.O distances of 2.30 and 2.46 A], whereas the molecules are interconnected through intermolecular C[bond]H...O hydrogen bonds [3.335 (4)-3.575 (5) A].
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, PO Box 537, SI-1001 Ljubljana, Slovenia. ivan.leban@uni-lj.si
authors.forename: Ivan
authors.initials: I
authors.lastname: Leban
authors.forename: Lovro
authors.initials: L
authors.lastname: Selic
authors.forename: Tomaz
authors.initials: T
authors.lastname: Mesar
authors.forename: Anton
authors.initials: A
authors.lastname: Copar
authors.forename: Tom
authors.initials: T
authors.lastname: Solmajer
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry*; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D065093:beta-Lactamase Inhibitors
chemical_list: D001372:Aza Compounds; D004791:Enzyme Inhibitors; D006575:Heterocyclic Compounds, 3-Ring; C464683:allyl-(4,8,9)-10-(ethylidene)-4-methoxy-11-oxo-1-azatricyclo(7.2.0.0(3,8))undec-2-ene-2-carboxylate; D065093:beta-Lactamase Inhibitors