75993-26-9Relevant academic research and scientific papers
Thermal valence isomerization of cis-fused bicyclic cyclobutenes. A study of orbital symmetry control
Dauben, William G.,Michno, Drake M.
, p. 2284 - 2292 (2007/10/19)
This study shows that thermally promoted valence isomerizations of cis-fused bicyclic cyclobutenes, when free of steric constraint, yield products arising from both orbital symmetry allowed conrotatory openings of the labile σ bond in the cyclobutene ring. In the case of the related vinylcyclobutenes, one conrotatory mode produces a stable cis,trans,cis monocyclic triene whereas fission in the other allowed sense affords a thermally labile trans,cis,cis monocyclic triene which, in turn, cyclizes to yield a cyclohexadiene derivative. The product distributions are evaluated in terms of secondary orbital interactions.
