title: Iridium-catalyzed oxidative lactonization and intramolecular Tishchenko reaction of delta-ketoaldehydes for the synthesis of isocoumarins and 3,4-dihydroisocoumarins.
abstract: Two new cyclizations of ketoaldehydes have been developed using an Ir-ligand bifunctional catalyst. Oxidative lactonization of delta-ketoaldehydes proceeded smoothly at room temperature to give coumarin derivatives in excellent yields. Intramolecular Tishchenko reaction of delta-ketoaldehydes afforded 3,4-dihydroisocoumarins in good yields.
authors.affiliation: Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-Ku, Sendai, Miyagi 981-8558, Japan.
authors.forename: Takeyuki
authors.initials: T
authors.lastname: Suzuki
authors.forename: Taichiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Tadashi
authors.initials: T
authors.lastname: Katoh
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D003374:Coumarins / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D000447:Aldehydes; D003374:Coumarins; D007495:Iridium