Chemistry of dioxine-annelated cycloheptatriene endoperoxides and their conversion into tropolone derivatives: an unusual non-benzenoid singlet oxygen source

Dastan A., Balci M.

TETRAHEDRON, vol.62, no.17, pp.4003-4010, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 62 Issue: 17
  • Publication Date: 2006
  • Doi Number: 10.1016/j.tet.2006.02.026
  • Journal Name: TETRAHEDRON
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.4003-4010
  • Middle East Technical University Affiliated: No


The chemistry of two bicyclic endoperoxides, obtained by photooxygenation of 2,3-dihydro-7H-cyclohepta[1,4]dioxine and 2,3-dihydro-7H-cyclohepta[b][1,4]dioxin-7-one was investigated with the aim of synthesizing the respective tropolone derivatives. The reaction of these endoperoxides with base, thiourea and their thermolysis provided the desired tropolone derivatives in high yield. On the other hand, the thermolysis of the endoperoxide derived from 2,3-dihydro-7H-cyclohepta[b] [ 1,4]dioxin-7-one underwent an unprecedented route and formed parent Molecule and singlet oxygen instead of the expected troponoids. The formation mechanisms of all products are discussed. (c) 2006 Elsevier Ltd. All rights reserved.