title: Rh-Catalyzed Cyclization of 3-Aryloxycarbonyldiazonaphthoquinones for the Synthesis of β-Phenylnaphthalene Lactones and Formal Synthesis of Pradimicinone.
abstract: In this study, we developed a novel method for the synthesis of β-phenylnaphthalene lactones. The diazo-transfer reactions of 2-azido-1,3-dimethylimidazolinium chlorides to 3-aryloxycarbonyl-1-naphthols proceeded smoothly to give corresponding 3-aryloxycarbonyldiazonaphthoquinones in high yields. These intermediates were further transformed to β-phenylnaphthalene lactones through a Rh-catalyzed intramolecular formal C-H insertion reaction. This method of lactone formation was efficiently applied to the formal total synthesis of pradimicinone.
authors.affiliation: Department of Applied Chemistry, Kyushu Institute of Technology, 1-1 Sensuicho, Tobata, Kitakyushu 804-8550 Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kitamura
authors.affiliation: Department of Applied Chemistry, Kyushu Institute of Technology, 1-1 Sensuicho, Tobata, Kitakyushu 804-8550 Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Applied Chemistry, Kyushu Institute of Technology, 1-1 Sensuicho, Tobata, Kitakyushu 804-8550 Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Okauchi