Synthesis and structure of systems containing pyramidalized and strained double bond: An investigation on the cycloaddition reactions of cis-and trans-3,8-dicarbomethoxy-3,8-dihydroheptalene

Saracoglu N., Menzek A., Balci M.

TURKISH JOURNAL OF CHEMISTRY, vol.25, no.1, pp.123-133, 2001 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 25 Issue: 1
  • Publication Date: 2001
  • Journal Indexes: Science Citation Index Expanded, Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.123-133


The cycloaddition reactions of cis-3,8-dicarbomethoxy-3,8-dihydroheptalene cis-2 and trans-3,8-dicarbomethoxy-3,8-dihydroheptalene trans-2 with various dienophiles such as dimethyl acetylenedicarboxylate (DMAD), p-benzoquinone. maleic anhydride, tetracyanoethylene, naphtoquinone gave monoaddition products 15-23. Further addition of benzyne and dimethyl acetylenedicarboxylate to 18 resulted in the formation of the compounds syn-25 and syn-26 having pyramidalized double bonds. The addition of benzyne to 21 and the addition of dimethyl acetylenedicarboxylate to 21, 22 and 23 gave the anti configuration products anti-26, 27 and 28: respectively. X-ray structures of syn-25, syn-26 and anti-26 show the pyramidalized angles to be 16.5 degrees, 19.9 degrees and 8.0 degrees respectively.