Synthesis 1990; 1990(2): 144-147
DOI: 10.1055/s-1990-26815
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Ein effizienter Zugang zu 1,5-Dihydropentalen und 2-Methyl-1,5-dihydropentalen aus Acrolein und Methacrolein

Axel G. Griesbeck*
  • *Institut für Organische Chemie der Universität Würzburg, Am Hubland, D-8700 Würzburg Federal Republic of Germany
Further Information

Publication History

Publication Date:
17 September 2002 (online)

Acrolein and methacrolein can be converted into 1,5-dihydropentalene and its 2-methyl derivative, respectively, by a simple, three-step process. [4+2]Cycloaddition of the aldehydes with cyclopentadiene affords 5-formyl-2-norbornenes which readily undergo condensation with cyclopentadiene to give 5-(cyclopentadienylidenemethyl)-2-norbornenes. These protected 6-vinylpentafulvenes undergo retro-cleave to cyclopentadiene and the 1,5-dihydropentalenes on vacuum flash thermolysis.

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