Studies on Heterocyclic Analogs of Azulene. VI. Cycloadditions of Styryl-substituted Aza Analogs of Azulene with Dimethyl Acetylenedicarboxylate
Autor: | Noritaka Abe, Tarozaemon Nishiwaki |
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Rok vydání: | 1980 |
Předmět: | |
Zdroj: | Bulletin of the Chemical Society of Japan. 53:1406-1413 |
ISSN: | 1348-0634 0009-2673 |
DOI: | 10.1246/bcsj.53.1406 |
Popis: | 8-[(E)-Styryl]-1-azaazulenes stereospecifically react with dimethyl acetylenedicarboxylate to form trans-7H-6a-azacyclobuta[j]cyclopent[cd]azulene (3), which undergoes thermal rearrangement into 3-[(E)-styryl]3H-2a-azacyclopent[cd]azulene and 3a,4-dihydro-3H-2a-azadicyclopent[cd, ij]azulene (7), or isomerization into 3H-2a-azacyclopenta[ef]heptalene by silica gel. Compound 7 is oxidized during the course of reaction to yield 11-oxo-2aH-7,10b-methano-2a-azacyclopenta[ab]cycloundecene, compound 3 forming 5a,6-dihydro-3H-2a-azadicyclopenta[ef, kl]heptalene upon reaction with acetylene. The formation of 3 could be accounted for in terms of a symmetry-allowed thermal [π2s+π2a+π6a] cycloaddition. |
Databáze: | OpenAIRE |
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