title: [6-endo-trig mode cyclization to a hydrindanone using samarium (II) iodide].
abstract: Samarium (II) iodide has been employed to promote the vinylogous pinacol coupling reaction of aldehyde to alpha, beta-unsaturated ketones. The diastereoselectivity of 6-endo-trig mode products was changed by the addition of a proton source and/or HMPA and by the reaction temperature. The stereochemistry of the hydrindanone was controlled by the coordinated samarium species, resulting in the cis-orientation in respect of the hydroxyl group at C-4 and the juncture proton at C-3a under mild reaction conditions. Coronafacic acid has been synthesized from a hydrindanone prepared by the cyclization reaction of the enone-aldehyde with samarium (II) iodide.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan. sono@ph.bunri-u.ac.jp
authors.forename: Masakazu
authors.initials: M
authors.lastname: Sono
mesh_terms: D003500:Cyclization; D003516:Cycloparaffins / Q000138:chemical synthesis*; D007192:Indenes / Q000138:chemical synthesis; D007454:Iodides; D008968:Molecular Conformation; D012493:Samarium; D013237:Stereoisomerism
chemical_list: D003516:Cycloparaffins; D007192:Indenes; D007454:Iodides; D012493:Samarium; C084266:coronafacic acid; C409809:samarium diiodide