Photochemical studies-XXI. Dimers of 3,4-(o,o'-biphenylene)cyclopentadienones: Thermal and photochemical behaviour

Benzion Fuchs*, Mordechai Pasternak

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The 1,4-dimethyl-, 1,2,4-trimethyl and 1,2,4,7-tetramethyl substituted 3,4-(o,o'-biphenylene) cyclopentadienone-dimers (6a-6c) were prepared and found to undergo photochemically or thermally a 1,3-rearrangement to the centrosymmetrical diketones (11). Only the tetramethyl derivative (6a) undergoes at room temperature a fast, degenerate [3.3] Cope rearrangement with ΔG233 = 11.4 kcal mol.-1 All these dimers and rearrangement products appear not to dissociate to their monomers, but react with dienophiles to give the adducts (12, 13). A stepwise mechanism involving diradical intermediates (19) is invoked. The "mixed dimer" (14) was also prepared and studied. The steric and electronic effects determining the behaviour of these compounds are discussed.

Original languageEnglish
Pages (from-to)2501-2507
Number of pages7
JournalTetrahedron
Volume37
Issue number14
DOIs
StatePublished - 1981

Fingerprint

Dive into the research topics of 'Photochemical studies-XXI. Dimers of 3,4-(o,o'-biphenylene)cyclopentadienones: Thermal and photochemical behaviour'. Together they form a unique fingerprint.

Cite this