Ether hydrolysis

[663697]

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I'm having trouble understanding why II is more easily hydrolyzed than I in the case of acid hydrolysis. Is it because the 2nd electronegative O is closer and pulls more electron density compared to its position in compound I?

 

[aldol16]

I'm having trouble understanding why II is more easily hydrolyzed than I in the case of acid hydrolysis. Is it because the 2nd electronegative O is closer and pulls more electron density compared to its position in compound I?

Yes.

 

[663697]

Yes.

Just a follow-up question -- when comparing the electrophilicity of 2 different carbonyl carbons, such as between an aldehyde and a ketone, do we only take into account the electron-donating nature if the R groups are alkyl groups? I've only come across a discussion of EDG's reducing the positive nature of the carbonyl carbon of ketones in contrast to aldehydes, so I was wondering if this still applies in cases like acyl halides or carboxylic acids.

 

[Nugester]

Just a follow-up question -- when comparing the electrophilicity of 2 different carbonyl carbons, such as between an aldehyde and a ketone, do we only take into account the electron-donating nature if the R groups are alkyl groups? I've only come across a discussion of EDG's reducing the positive nature of the carbonyl carbon of ketones in contrast to aldehydes, so I was wondering if this still applies in cases like acyl halides or carboxylic acids.

Top of my head, EDGs are usually alkyl. But remember, nitrogen can be ...like NH2.

 

[aldol16]

Just a follow-up question -- when comparing the electrophilicity of 2 different carbonyl carbons, such as between an aldehyde and a ketone, do we only take into account the electron-donating nature if the R groups are alkyl groups? I've only come across a discussion of EDG's reducing the positive nature of the carbonyl carbon of ketones in contrast to aldehydes, so I was wondering if this still applies in cases like acyl halides or carboxylic acids.

Well, let's keep what we're comparing clear here. If we're comparing ketones and aldehydes, ketones have one more alkyl group than the aldehyde and so you can rationalize the electronics about the carbonyl using electron-donation by that extra alkyl group. But acyl halides or carboxylic acids are different because you're making a different comparison. You're comparing acyl halides to, say, aldehydes. And the difference there is a halogen versus hydrogen - obviously the halogen will be more electron-withdrawing than the hydrogen and therefore will increase the electrophilicity of the carbonyl. You could also compare an acyl halide with a ketone (a less frequent comparison) and still find that the acyl halide will increase the electrophilicity of the carbonyl relative to the ketone since alkyl is donating and halide is electron-withdrawing.