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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: bluecrayon on April 07, 2012, 05:17:16 PM

Title: Why does this favour the product (hydration of ketone)?
Post by: bluecrayon on April 07, 2012, 05:17:16 PM

So I'm studying from my textbook for my Organic 2 final and it asked me an interesting question:

"For most ketone's hydrate formation is unfavourable because the equilibrium favours the ketone rather than the hydrate however the equilibrium for hydration of hexafluoroacetone favours formation of hydrate. Provide plausible reason why?"

The nucleophile H2O is a good leaving group so I don't see why it would want to even stay on the induced carbon atom. Does the fluorine do something that I am missing?

I also noticed my book say something like formaldehyde favours the hydrade but didn't explain why. I'm guessing it's for similar reasons.

Any ideas?

edit: made this for visual reference on what I am speaking of:
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Foi40.tinypic.com%2F16l0f4j.jpg&hash=897dbf5c6cb5509b09d825ea1f02a2ebee314454)

Title: Re: Why does this favour the product (hydration of ketone)?
Post by: Hand15 on April 08, 2012, 03:17:08 AM

This has something to do with the inductive effect exerted by six atoms of fluorine.
Ordinary ketone won't favor the formation of hydrate as it is not electrophilic enough.