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Topic: Hydroboration Diastereoselectivity and Odd Newman Projection  (Read 3215 times)

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Offline omegasynthesis999

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Hydroboration Diastereoselectivity and Odd Newman Projection
« on: April 04, 2008, 10:15:36 PM »
See attached rxn.

Product 1 (on the left is favored). I know this has to do with sterics in the sense that when the R2BH approaches to add to the double bond, sterics on the chirality center can hinder this. However, of the two Newman structures I have drawn, which one is more stable? If neither is stable, what arrangements of atoms would be most stable? Which Newman projection would lead to the preferred product?

Thanks

Offline Structuralist

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Re: Hydroboration Diastereoselectivity and Odd Newman Projection
« Reply #1 on: April 06, 2008, 08:34:45 AM »
Here is one good representation of the projections http://www.bluffton.edu/~bergerd/models/newman.html
the staggered one is the most stable because all the atoms are as much as possible far away from each other, unlike the situation with the eclipse conformation.

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