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Topic: Problem of the Week 08/03/09  (Read 5935 times)

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Offline azmanam

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Problem of the Week 08/03/09
« on: August 03, 2009, 08:11:54 AM »
QUESTION:  The acid catalyzed cyclization of the trans epoxide starting material yields a single kinetic product.  Predict the kinetic product of this reaction and the relative stereochemistry of the product.  Provide a visual orbital explanation that accounts for the selectivity of this process.
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Offline azmanam

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Re: Problem of the Week 08/03/09
« Reply #1 on: August 06, 2009, 07:27:07 AM »
*Ignore me, I am impatient*
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Offline sjb

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Re: Problem of the Week 08/03/09
« Reply #2 on: August 06, 2009, 04:10:47 PM »
Well, I think the answer is probably related to Baldwin's guidelines, but then again I thought these did not really apply to acidic solutions. If I'm on the right track, I think the tetrahydrofuran ring is the preferred product. Not 100% sure of stereochem, I'll keep scratching my head.

Offline azmanam

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Re: Problem of the Week 08/03/09
« Reply #3 on: August 06, 2009, 04:13:04 PM »
on the right track.  It's not formally Baldwin, but - er - Baldwin-esque.
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Offline blind

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Re: Problem of the Week 08/03/09
« Reply #4 on: August 28, 2009, 11:17:36 AM »
A bit late to the party, but could it be because of better overlap of the lone pairs on the oxygen with the antibonding orbitals of C-O bond in the formation of THF?


Offline azmanam

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Re: Problem of the Week 08/03/09
« Reply #5 on: August 28, 2009, 11:22:42 AM »
That is in fact why.  Well done.  Orbital overlap is what drives most of Baldwin's rules, if I'm not mistaken.

Sorry for not posting new questions.  I got caught up in back-to-school and applying-for-job stuff.  I'll get a new one up mondayish
Knowing why you got a question wrong is better than knowing that you got a question right.

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