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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: joyb on February 26, 2013, 10:01:47 AM

Title: Why are ethers unreactive?
Post by: joyb on February 26, 2013, 10:01:47 AM: I would think that their high polarity would make the oxygen atom very susceptible to hydrolysis. Why are they so unreactive? Steric hindrance?
Title: Re: Why are ethers unreactive?
Post by: Babcock_Hall on February 26, 2013, 10:27:11 AM: Draw out the mechanism and ask yourself what the leaving group would be.
Title: Re: Why are ethers unreactive?
Post by: joyb on February 26, 2013, 02:35:34 PM: So is it just that the leaving group would have to be an alkyl group?
Title: Re: Why are ethers unreactive?
Post by: Altered State on February 26, 2013, 02:55:30 PM: Quote from: amberbarton on February 26, 2013, 02:35:34 PM
So is it just that the leaving group would have to be an alkyl group?

Isn't it good enough reason?
Title: Re: Why are ethers unreactive?
Post by: Babcock_Hall on February 26, 2013, 05:09:15 PM: Quote from: amberbarton on February 26, 2013, 02:35:34 PM
So is it just that the leaving group would have to be an alkyl group?
I pictured diethyl ether in my mind, and I may be thinking of a different chemical process than you are. If solvent attacked the carbon atom of the -CH₂- group, then ethoxide would be the leaving group. This would not be a fast process.
Title: Re: Why are ethers unreactive?
Post by: camptzak on February 27, 2013, 12:35:29 AM: What pH (acid or base) do ethers hydrolyze at? I found a paper that might contain the answer but I do not have access!
http://pubs.acs.org/doi/abs/10.1021/ie0702882
Title: Re: Why are ethers unreactive?
Post by: Altered State on February 27, 2013, 09:59:07 AM: Quote from: camptzak on February 27, 2013, 12:35:29 AM
What pH (acid or base) do ethers hydrolyze at? I found a paper that might contain the answer but I do not have access!
http://pubs.acs.org/doi/abs/10.1021/ie0702882

Always Acid Media to break an ether C-O Bond, and it's always broken the less substituted Carbon bond.
What pH? It depends on the ether.
For example, dibuthyl ether would be way easier to hydrolyze than diphenylether (which one is extremelly difficult).

You also have to consider the exception of epoxides, that can be easily opened both in basic media (less substituted C) and acid media (most substituted).
Title: Re: Why are ethers unreactive?
Post by: Babcock_Hall on February 27, 2013, 10:32:39 AM: At room temperature, the reaction is specific-acid catalyzed, according to the paper.