Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven
In contrast to earlier assumptions, thermal reaction of simple fulvenes 1a, b, c at 20°C gives Diels-Alder-dimers 2a, b, c in a relatively high yield. Whereas the dimers 2b and 2c equilibrate easily with the corresponding fulvenes at 60 °C, heating of the fulvene-dimer 2a produces an equilibrium 2a...
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| Format: | Article |
| Language: | deu |
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Swiss Chemical Society
1981-10-01
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| Series: | CHIMIA |
| Online Access: | https://www.chimia.ch/chimia/article/view/9536 |
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| _version_ | 1850140254118346752 |
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| author | Beat Uebersax Markus Neuenschwander |
| author_facet | Beat Uebersax Markus Neuenschwander |
| author_sort | Beat Uebersax |
| collection | DOAJ |
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In contrast to earlier assumptions, thermal reaction of simple fulvenes 1a, b, c at 20°C gives Diels-Alder-dimers 2a, b, c in a relatively high yield. Whereas the dimers 2b and 2c equilibrate easily with the corresponding fulvenes at 60 °C, heating of the fulvene-dimer 2a produces an equilibrium 2a ⇄ 3a. After heating of pure 6,6-dimethylfulvene (1c) for several months at 60°C, a trimeric product 6c is isolated with a 35 % yield (60 % with respect to reacted 1c). Formation of 6c may be explained by a thermodynamically controlled [6 + 4]-cycloaddition of 2 molecules of 1c, followed by a 1,5-H-shift as well as by Diels-Alder-reaction of 5c with a third fulvene molecule.
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| format | Article |
| id | doaj-art-fa6202e52f5c4dc0941a8159cd6679f6 |
| institution | OA Journals |
| issn | 0009-4293 2673-2424 |
| language | deu |
| publishDate | 1981-10-01 |
| publisher | Swiss Chemical Society |
| record_format | Article |
| series | CHIMIA |
| spelling | doaj-art-fa6202e52f5c4dc0941a8159cd6679f62025-08-20T02:29:54ZdeuSwiss Chemical SocietyCHIMIA0009-42932673-24241981-10-01351010.2533/chimia.1981.400Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-DimethylfulvenBeat Uebersax0Markus Neuenschwander1Institut für Organische Chemie, Universität Bern, CH-3012 Bern, Freiestrasse 3Institut für Organische Chemie, Universität Bern, CH-3012 Bern, Freiestrasse 3 In contrast to earlier assumptions, thermal reaction of simple fulvenes 1a, b, c at 20°C gives Diels-Alder-dimers 2a, b, c in a relatively high yield. Whereas the dimers 2b and 2c equilibrate easily with the corresponding fulvenes at 60 °C, heating of the fulvene-dimer 2a produces an equilibrium 2a ⇄ 3a. After heating of pure 6,6-dimethylfulvene (1c) for several months at 60°C, a trimeric product 6c is isolated with a 35 % yield (60 % with respect to reacted 1c). Formation of 6c may be explained by a thermodynamically controlled [6 + 4]-cycloaddition of 2 molecules of 1c, followed by a 1,5-H-shift as well as by Diels-Alder-reaction of 5c with a third fulvene molecule. https://www.chimia.ch/chimia/article/view/9536 |
| spellingShingle | Beat Uebersax Markus Neuenschwander Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven CHIMIA |
| title | Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven |
| title_full | Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven |
| title_fullStr | Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven |
| title_full_unstemmed | Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven |
| title_short | Fulven-Dimere und -Trimere. Hinweis auf eine [6 + 4]-Cycloaddition von 6,6-Dimethylfulven |
| title_sort | fulven dimere und trimere hinweis auf eine 6 4 cycloaddition von 6 6 dimethylfulven |
| url | https://www.chimia.ch/chimia/article/view/9536 |
| work_keys_str_mv | AT beatuebersax fulvendimereundtrimerehinweisaufeine64cycloadditionvon66dimethylfulven AT markusneuenschwander fulvendimereundtrimerehinweisaufeine64cycloadditionvon66dimethylfulven |