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Topic: Thinking backwards in pericyclic reactions  (Read 3448 times)

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Offline Rutherford

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Thinking backwards in pericyclic reactions
« on: April 05, 2015, 11:49:27 AM »
How to think of a way to synthesize the attached molecule? I have found that it can be easily synthesized with parabenzoquinone and 1,3-cyclohexadiene in a Diels-Alder addition, followed by a photochemically induced [2+2] cycloaddition. Are there any tricks and tips of how to think when doing such problems?

Offline Rutherford

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Re: Thinking backwards in pericyclic reactions
« Reply #1 on: April 05, 2015, 02:14:50 PM »
For example, how to deduce the starting materials for the following compound:
« Last Edit: April 05, 2015, 02:36:02 PM by Rutherford »

Offline clarkstill

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Re: Thinking backwards in pericyclic reactions
« Reply #2 on: April 05, 2015, 04:41:33 PM »
Diels alder between furan and benzyne, then partial ozonolysis to make the secondary ozonide?

Offline Rutherford

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Re: Thinking backwards in pericyclic reactions
« Reply #3 on: April 06, 2015, 01:54:53 PM »
Could there be a pathway with singlet oxygen?

Offline clarkstill

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Re: Thinking backwards in pericyclic reactions
« Reply #4 on: April 06, 2015, 02:46:35 PM »
Not that I can see. The only place singlet oxygen could be incorporated is where the peroxy ether is, but I don't see how this could easily arise through cycloaddition chemistry with anything that looks reasonable.

Offline Rutherford

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Re: Thinking backwards in pericyclic reactions
« Reply #5 on: April 06, 2015, 03:45:43 PM »
How does the ozonide formation work?

Offline Dan

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Re: Thinking backwards in pericyclic reactions
« Reply #6 on: April 07, 2015, 03:02:15 AM »
How does the ozonide formation work?

Google "ozonolysis mechanism", or look it up in any organic chemistry textbook. It's a classic.
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Offline clarkstill

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Re: Thinking backwards in pericyclic reactions
« Reply #7 on: April 07, 2015, 10:52:34 AM »
See attached.

Offline Rutherford

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Re: Thinking backwards in pericyclic reactions
« Reply #8 on: April 07, 2015, 12:52:24 PM »
Now I understand. Thank you very much.

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