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Photocycloaddition of 4-(Alk-1-ynyl)-Substituted Coumarins and Thiocoumarins to 2,3-Dimethylbuta-1,3-diene

✍ Scribed by Inga Inhülsen; Karin Chin; Maren Göwert; Paul Margaretha

Publisher
John Wiley and Sons
Year
2011
Tongue
German
Weight
144 KB
Volume
94
Category
Article
ISSN
0018-019X

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✦ Synopsis

On irradiation (350 nm) in the presence of 2,3-dimethylbuta-1,3-diene (8), 4-(alk-1-ynyl)coumarins 1 afford mixtures of cyclobuta-and cycloocta-annulated products 9 and 10, respectively. In contrast, the corresponding thiocoumarins 2 react with the same diene chemoselectively to give cyclohexa-annulated products 11.

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