- Anodic oxidation of cycloheptatriene systems and its application to the synthesis of non-benzenoid aromatic compounds
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Anodic oxidation of cycloheptatrienes has been found to be one of the most powerful key tools for the preparation of a variety of non-benzenoid aromatic compounds such as tropylium salts, tropones, tropolones, 2H-cyclohepta[b]furan-2-ones, and azulenes.
- Shono, Tatsuya,Nozoe, Tetsuo,Maekawa, Hirofumi,Yamaguchi, Yoshihide,Kanetaka, Shinya,Masuda, Haruhisa,Okada, Toshio,Kashimura, Shigenori
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p. 593 - 603
(2007/10/02)
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- ANODIC TRANSFORMATION OF CYCLOHEPTATRIENE TO TROPONE AND TROPOLONE
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Cycloheptatriene (CHT) has been directly transformed to 7-methoxycycloheptatriene (7-MCHT), an equivalent compound to a tropolium salt, by the anodic oxidation of CHT in methanol.The further anodic oxidation of 3-MCHT prepared from 7-MCHT has been found to be an effective method of synthesis of tropone and tropolone.
- Shono, Tatsuya,Nozoe, Tetsuo,Maekawa, Hirofumi,Kashimura, Shigenori
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p. 555 - 558
(2007/10/02)
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- A Photoinduced Two Carbon Ring Expansion leading to an Easy Synthesis of γ-Tropolone
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Irradiation of 3-methoxycyclopent-2-en-1-one (1) and an excess of acetylene in MeCN at O deg C with Pyrex-filtered light from a Hg-lamp gives 5-methoxycyclohepta-2,4-dien-1-one (2), which undergoes SeO2 oxidation to 4-methoxytropone (3), a known source of γ-tropolone (4); using dideuterioacetylene in place of acetylene, a 3:2 mixture of the isomeric 2,3- and 3,4-dideuterio analogues of (2) is obtained, suggesting a limitation of this method for substituted γ-tropolones.
- Cavazza, Marino,Pietra, Francesco
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p. 1480 - 1481
(2007/10/02)
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- The Sensitized Photooxidation of Methoxycycloheptatrienes. The Synthesis of α-, β-, and γ-Tropolones
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The sensitized photooxidation of 7-methoxycycloheptatriene (7-methoxytropilidene) afforded cycloadduct (2), tropone, benzaldehyde and their 2-methoxy derivatives.Thermal isomerization of 2 followed by the treatment with alumina yielded 4-methoxytropone.The photooxidation of 1-methoxytropilidene gave 4-hydroxytropone and o-methoxybenzaldehyde, and the photooxidation of 3-methoxytropilidene followed by the treatment with triethylamine afforded 3-methoxytropone, tropone, and o-methoxybenzaldehyde.Characterization of the products and the mechanisms of the reactions are discussed.
- Yagihara, Morio,Kitahara, Yoshio,Asao, Toyonobu
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p. 236 - 238
(2007/10/02)
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