Diels-Alder reaction of α-tropolone and electron-deficient dienophiles prompted by Et3N or silica gel: a new synthetic method of highly functionalized homobarrelenone derivatives

Hiroaki Okamura, Hiroki Iiji, Toshiyuki Hamada, Tetsuo Iwagawa, Hiroshi Furuno

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

A Diels-Alder reaction of α-tropolone and electron-deficient dienophiles prompted by Et3N or silica gel was performed. Reaction with the highly reactive dienophile, N-methylmaleimide, proceeded smoothly in the presence of Et3N or silica gel to yield adducts as a mixture of endo and exo isomers. Both catalysts accelerated endo/exo isomerization of the product, and detailed examination of the reaction using hinokitiol and N-methylmaleimide revealed that isomerization proceeds via an intramolecular path without retro Diels-Alder reaction. Successful cycloaddition reactions were established with six other dienophiles: acrylonitrile, methyl acrylate, ethyl vinyl ketone, dimethyl fumalate, dimethyl malate, and dimethyl acetylenedicarboxylate, and the corresponding adducts were obtained in good to moderate yields.

Original languageEnglish
Pages (from-to)10709-10714
Number of pages6
JournalTetrahedron
Volume65
Issue number51
DOIs
Publication statusPublished - Dec 19 2009

Fingerprint

Tropolone
Silica Gel
Cycloaddition Reaction
Isomerization
Electrons
Acrylonitrile
Derivatives
Cycloaddition
Isomers
Catalysts
N-methylmaleimide

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

Cite this

Diels-Alder reaction of α-tropolone and electron-deficient dienophiles prompted by Et3N or silica gel : a new synthetic method of highly functionalized homobarrelenone derivatives. / Okamura, Hiroaki; Iiji, Hiroki; Hamada, Toshiyuki; Iwagawa, Tetsuo; Furuno, Hiroshi.

In: Tetrahedron, Vol. 65, No. 51, 19.12.2009, p. 10709-10714.

Research output: Contribution to journalArticle

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