Elimination of alcohols to give alkenes using POCl3

by James

Description: When treated with phosphorus oxychloride (POCl3) alcohols are converted to alkenes via an elimination reaction.
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{ 6 comments… read them below or add one }

Joseph Blair June 30, 2012 at 9:46 pm

Please forgive if this is an elementary question, but I am trying to extract information that was last used when a 128k Macintosh was 1600.00. The POCl3 : the electronegativities sandwich the poor little P between a rock and a hard place. The Cl wants the density in 3 directions but the O wants it more by .97. Without getting into the vector analysis, will the Cl’s be pulled upward in the same manner but different direction, as H’s in H2O are bent away the electrons on the O.

Sorry, for what I think Brother Adrian called, Illigitimus Parenthetica.

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Quinn Haynie March 20, 2013 at 9:28 pm

Electronegativity: O=3.44, Cl=3.16. As I understand, the chlorines will minimize repulsive forces by settling into the optimal angle from the oxygen. The Cl-Cl angles should be the same, and the Cl-O angle should be slightly larger than Cl-Cl. Exact numbers? Try scientific literature!

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navjot June 12, 2013 at 2:57 pm

Does this elimination involves an intermediate carbocation? Please if u could tell me !!

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james June 19, 2013 at 9:03 pm

No, I believe this is essentially an E2 reaction.

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Alexander Peltekoff October 11, 2013 at 5:00 am

We were taught that pyridine has to be present for this reaction to take place. Is it not necessary?

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James Ashenhurst October 18, 2013 at 2:07 pm

Pyridine would significantly improve the rate of reaction. I’d put it in. Need to update this page to show that. Thanks!

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