Maerkl, Gottfried and Sauer, Heinrich and Kreitmeier, Peter and Burgemeister, Thomas and Kastner, Fritz (1999) Synthesis of diepoxy[16]annulene(6.2) by intramolecular McMurry coupling. TETRAHEDRON, 55 (47). pp. 13407-13416. ISSN 0040-4020,
Full text not available from this repository.Abstract
The synthesis of diepoxy[16]annulene(6.2) 3 is described. The dialdehyde (E,E)-3,3'-([2,2'-bifuran]-5.5'-diyl)bis[2-propenal] 4 undergoes an intramolecular as well as an intermolecular McMurry coupling to give the diepoxy[16]annulene 3 beside the tetraepoxy[32]annulene(6.2.6.2) (5), According to the spectroscopic data 3 has the Z,Z,E,Z-configuration and it turns out to be a strongly paratropic, highly dynamic system, where the E-ethsnediyl-1,2-bond rotates around the adjacent single bonds. According to VT-H-1-NMR spectroscopy, this rotation is even not yet entirely frozen at -130 degrees C. The calculated free activation energy of the rotation is about 24 kJ/mol (5,74 kcal/mol), the smallest value observed ever for the rotation of E-ethenediyl-1,2-bonds in annulenes. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 13 Dec 2022 06:00 |
| Last Modified: | 13 Dec 2022 06:00 |
| URI: | https://pred.uni-regensburg.de/id/eprint/48828 |
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