title: Valuable new cyclohexadiene building blocks from cationic η5-iron-carbonyl complexes derived from a microbial arene oxidation product.
abstract: Biooxidation of benzoic acid by Ralstonia eutropha B9 provides an unusual cyclohexadiene carboxy diol that contains a quaternary stereocentre. Tricarbonyliron derivatives of this chiron, on treatment with acid, give two isomeric η(5)-cyclohexadienyl complexes as observed by NMR spectroscopy. Both of these can be subjected to the addition of nucleophiles to provide isomeric cyclohexadiene complexes with new substituent patterns, several of which have been characterised crystallographically. De-metallation of these provides a versatile library of cyclohexadiene building blocks, the utility of which is demonstrated by formal syntheses of oseltamivir. The mechanism of product formation and its stereochemical implications are discussed, as are the procedures undertaken to establish the enantiopurity of a representative cyclohexadiene product.
authors.affiliation: Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY UK.
authors.forename: Monika
authors.initials: M
authors.lastname: Ali Khan
authors.forename: Mary F
authors.initials: MF
authors.lastname: Mahon
authors.forename: John P
authors.initials: JP
authors.lastname: Lowe
authors.forename: Alan J W
authors.initials: AJ
authors.lastname: Stewart
authors.forename: Simon E
authors.initials: SE
authors.lastname: Lewis
mesh_terms: D019817:Benzoic Acid / Q000737:chemistry / Q000378:metabolism; D002412:Cations / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D020118:Cupriavidus necator / Q000378:metabolism; D053138:Cyclohexenes / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D008968:Molecular Conformation; D053139:Oseltamivir / Q000138:chemical synthesis / Q000737:chemistry; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D002412:Cations; D056831:Coordination Complexes; D053138:Cyclohexenes; D007659:Ketones; C048401:1,4-cyclohexadiene; D053139:Oseltamivir; D019817:Benzoic Acid; D007501:Iron