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Topic: Alkene equilibration Z-->E  (Read 2390 times)

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Offline jj74

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Alkene equilibration Z-->E
« on: November 12, 2010, 06:44:31 AM »
I came across this in Clayden organic chemistry. One of the way to equilibrate Z-alkene to E-alkene is addition of iodine to the double bond (reaction in attachement). What is not explained is how I go back to the olefin (E) when I have the diiodo derivate. Is there any particular reagent/method ?
thanks
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Offline AWK

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Re: Alkene equilibration Z-->E
« Reply #1 on: November 12, 2010, 07:10:10 AM »
This is rather catalysis, and not addition.
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Offline jj74

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Re: Alkene equilibration Z-->E
« Reply #2 on: November 12, 2010, 07:50:54 AM »
so iodine goes away spontaneously after rotation?
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Offline MOTOBALL

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Re: Alkene equilibration Z-->E
« Reply #3 on: November 13, 2010, 10:24:49 AM »
My recollection is that I2 adds very readily to >C=C<, but that vicinal di-iodo compounds are very unstable and will readily eliminate I2 spontaneously to give the -ene.

Thus the equilibrium condition is established very quickly.

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