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What are these pericyclic reactions?

  1. Dec 15, 2013 #1
    First one:
    is this an intramolecular [2+2] photocycloaddition?

    And this one:
    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.
  2. jcsd
  3. Dec 17, 2013 #2
    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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