title: Stereoselective synthesis of tetrasubstituted alkenes via torquoselectivity-controlled olefination of carbonyl compounds with ynolates.
abstract: The efficient synthesis of tetrasubstituted alkenes by the olefination of carbonyl compounds with ynolates is described. This reaction involves the cycloaddition of ynolates with carbonyl groups, followed by electrocyclic ring-opening of the resulting β-lactone enolates. Orbital symmetry during the electrocyclic ring opening requires conrotatory motion. The direction of this rotation (inward or outward) determines the E/Z geometry to the tetrasubstituted olefin product through torquoselectivity. Theoretical calculations revealed that several secondary orbital interactions are essential for the high torquoselectivity. This methodology is a novel olefination for constructing multisubstituted olefins.
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Japan. shindo@cm.kyushu-u.ac.jp
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shindo
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002625:Chemistry, Organic; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D002264:Carboxylic Acids; D006571:Heterocyclic Compounds; D007659:Ketones