Pyramidalized double bonds containing endoperoxide linkages:: Photooxygenation of dimethyl <i>cis</i>-3,8-dihydroheptalene-3,8-dicarboxylate

SARAÇOĞLU N., Menzek A., Sayan S., Salzner U., Balci M.

JOURNAL OF ORGANIC CHEMISTRY, cilt.64, sa.18, ss.6670-6676, 1999 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 64 Sayı: 18
  • Basım Tarihi: 1999
  • Doi Numarası: 10.1021/jo990393o
  • Dergi Adı: JOURNAL OF ORGANIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Index Chemicus (IC)
  • Sayfa Sayıları: ss.6670-6676
  • Ankara Üniversitesi Adresli: Hayır

Özet

Diels-Alder cyclo;addition utilizing singlet oxygen as the dienophile with dimethyl cis-3,8-dihydraheptalene-3,8-dicarboxylate (5) has been investigated, and monoaddition product 7 has been isolated. The addition of a second singlet oxygen to the cycloheptatriene unit in 7 gave syn-bis(norcaradiene) bis(endoperoxide) 4. H-1 NMR spectral studies and theoretical calculations indicate the increased pyramidalization in syn-4 compared with carbon analogue. The increased pyramidalization results from hyperconjugation between the central pi-bond and the four adjacent C-O bonds and by rehybridization at C3, C4, C5, and C6. Furthermore, the increased reactivity for syn-4, which is probably arising from further folding of the central double band, is also in agreement with theoretical calculations.