- Photoinduced Irreversible Intramolecular Proton Transfer of Arnebinones B, D, and E: The Case of Photoenolization at the p-Benzoquinone-CH2/CH-πSystem
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Arnebinones B, E, and D (1-3) have been found to be sensitive to light, generating complex and diverse proton transfer products when triggered by light. A unique two-step irreversible intramolecular proton transfer of 1 produced five scalemic mixtures, of
- Yan, Hai-Wei,Yang, Ya-Nan,Yuan, Xiang,Zhang, Pei-Cheng,Zhang, Xu,Zhao, Ling-Hao
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supporting information
p. 2981 - 2989
(2021/12/02)
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- Concise Synthesis of Chromene/Chromane-Type Aryne Precursors and Their Applications
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The gram-scale synthesis of 5,6-, 6,7-, and 7,8-chromene/chromane-type aryne precursors and their applications in regioselective transformation to other functional derivatives is reported. Chromene/chromane-type arynes are generated under mild conditions, which can further undergo [2 + 2], [3 + 2], and [4 + 2] cycloaddition reactions, nucleophilic addition reactions, and σ-insertion reactions to produce structurally novel substituted chromenes and chromanes. The excellent regioselectivity of the reaction is facilitated by the oxygen-containing guiding groups at the ortho-position of the triple bond, which can be removed or switched to other functional groups including alkenyl, aryl, heteroaryl, and arylamino groups.
- Xu, Yuan-Ze,Tian, Jia-Wei,Sha, Feng,Li, Qiong,Wu, Xin-Yan
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p. 6765 - 6779
(2021/05/06)
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- Efficient synthesis of precocenes
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Precocenes and related intermediates were synthesised in good yields using hydrogen peroxide, selenium dioxide and methylene chloride combination in the key step.
- Kulkarni,Paradkar
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p. 1555 - 1562
(2007/10/02)
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- Analogues of Antijuvenile Hormones
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Several analogues of precocenes I and II have been synthsized, including derivatives of 6,7-dihydroxy-2,2-dimethylchromen, 7,8-dihydroxy-2,2-dimethylchromen, 7-hydroxy-2,2-dimethyl-6-nitrochromene, and 6-amino-7-hydroxy-2,2-dimethylchromen. 5,6-Dimethoxy-3,3-dimethylindene was also synthesized.Improved procedures for the dehydration of chroman-4-ols to chromens and for the reduction of chroman-4-ones to chroman-4-ols are reported.Analogues have been tested for activity in the brown planthopper Nilaparvatus lugens Stal.None had significant morphogenetic effects, but two possessed insecticidal activity and showed both antagonism and synergism when used in cojunction with permethrin.
- Anastasis, Panayiotis,Brown, Philip E.
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p. 2013 - 2018
(2007/10/02)
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- Prenylation of methoxyhydroquinone in aqueous acid solution and an alternative synthesis of precocene II
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The acid-catalyzed condensation of methoxyhydroquinone with 2-methyl-3-buten-2-ol leads to 2-methoxy-5-(3-methyl-2-butenyl)hydroquinone (4) and 2-(1,1-dimethylallyl)-5-methoxyhydroquinone (7).Compound 4 can easily be converted into precocene II (1, R=Me).
- Uchiyama, M.,Overeem, J. C.
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p. 408 - 410
(2007/10/02)
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