What are these pericyclic reactions?

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SUMMARY

This discussion focuses on the mechanisms of pericyclic reactions, specifically intramolecular [2+2] photocycloaddition and intramolecular Alder-ene reactions involving cyclopropyl rings. Participants highlight the instability of cyclopropyl rings and their tendency to open during electrocyclizations, which plays a crucial role in the reaction pathways. The stabilization of positive charges by adjacent groups, such as carbonyl oxygens and methyl groups, is also emphasized as a significant factor in these reactions.

PREREQUISITES
  • Understanding of pericyclic reactions
  • Familiarity with intramolecular [2+2] photocycloaddition
  • Knowledge of Alder-ene reactions
  • Basic concepts of cyclopropyl ring stability
NEXT STEPS
  • Study the mechanisms of pericyclic reactions in detail
  • Learn about the role of cyclopropyl rings in organic chemistry
  • Investigate the effects of electron-donating groups in reaction stabilization
  • Explore the principles of electrocyclization and its applications
USEFUL FOR

Chemistry students, organic chemists, and researchers interested in reaction mechanisms and the behavior of cyclic compounds in pericyclic reactions.

CrimpJiggler
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First one:
feea75c6577d97b85310a41fb53f06bb.png

is this an intramolecular [2+2] photocycloaddition?

And this one:
aa86e2304119606f2535da3b00648cdc.png

I'm fairly confused about this one. Could it be an intramolecular Alder-ene reaction? Whats confusing me most is that cyclopropyl ring up there. I know they're pretty unstable and I read that they open during electrocyclisations and stuff like that so I'm wondering if it plays a role in this reaction.
 
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It's been a while since I studied chemistry, but since no one answered, I'll throw my 2 cents.

For #2:

It's a fairly safe bet that the cyclopropane ring will open, leaving a temporary + on the quaternary carbon. There are two things that make this easier: the carbonyl oxygen can donate electrons through the conjugated double bonds, and the + is stabilized by the methyl group.

Then, I think, the 6-membered ring will close with rearrangement of protons.
 

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