I tried to construct a correlation diagram for the [4+4] cyclo addition of two cis-butadiene units. But I failed to construct any meaning full orbitals for the "educt" side where the two butadiene molecules still have their pi-systems intact.

I thought that a C2 rotation axis is conserved during a supra-antarafacial reaction pathway but aligning the pi system of both units leads to a conflict. The backbone of the supra-facial part cannot be combined with the antarafacial unit to sustain C2 symmetry. This would only be possible for a combination of a cis-butadiene with a trans-butadiene. But without any conserved symmetry element correlation is impossible.

So I'm wondering if the Woodward-Hoffmann rules are applicable at all in this case or if I am being too strict with symmetry. Is it legit to neglect the backbone when thinking about the symmetry?

enter image description here



Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Browse other questions tagged or ask your own question.