title: Characterization of stereochemistry and molecular conformation using solid-state NMR tensors.
abstract: A solid-state NMR technique is described for establishing stereochemistry using the natural product terrein as a model compound. This method involves comparison of experimental (13)C tensor principal values with ab initio computed values for all possible computer-generated stereoisomers. In terrein the relative stereochemistry is confirmed by NMR to be 2R*,3S with high statistical probability (>99.5%). The proposed approach also simultaneously verifies the molecular conformation of the two hydroxy groups in terrein established by X-ray data. It is sufficient to use only shift tensor values at carbons 2 and 3, the stereocenters, to characterize both the stereochemistry and molecular conformations. The solid-state NMR method appears to be especially useful for determining relative stereochemistry of compounds or their derivatives that are difficult to crystallize.
authors.affiliation: Department of Chemistry, University of Utah, Salt Lake City, 84112, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Harper
authors.forename: A E
authors.initials: AE
authors.lastname: Mulgrew
authors.forename: J Y
authors.initials: JY
authors.lastname: Li
authors.forename: D H
authors.initials: DH
authors.lastname: Barich
authors.forename: G A
authors.initials: GA
authors.lastname: Strobel
authors.forename: D M
authors.initials: DM
authors.lastname: Grant
mesh_terms: D002247:Carbon Isotopes; D003517:Cyclopentanes / Q000737:chemistry*; D005658:Fungi / Q000737:chemistry; D008968:Molecular Conformation; D009183:Mycotoxins / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
chemical_list: D002247:Carbon Isotopes; D003517:Cyclopentanes; D009183:Mycotoxins; C439087:terrein