A new method for the synthesis of stipitatic acid isomers: Photooxygenation of ethyl 6H-cyclohepta[d][1,3]dioxole-6-carboxylate

Dastan A., Saracoglu N., Balci M.

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, no.18, pp.3519-3522, 2001 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2001
  • Journal Name: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3519-3522
  • Keywords: peroxides, fused-ring systems, natural products, singlet oxygen, photochemistry, BICYCLIC ENDOPEROXIDES
  • Middle East Technical University Affiliated: No

Abstract

Photooxygenation of the cycloheptatriene derivative 9 gave the bicyclic endoperoxide 14. Cleavage of the peroxide linkage in 14 with thiourea resulted in the formation of 16. Treatment of the endoperoxide 14 with a catalytic amount of triethylamine provided a new isomer of stipitatic acid 11, and 16. Pyrolysis or the CoTPP (TPP = tetraphenylporphyrin) catalyzed reaction of 14 resulted in the formation of iso-stipitatic acid 10, and 18,