ethyl benzoate

[lakers2009]

I know Benzoic acid and Ethanol can form Ethyl Benzoate. There's a problem in one of the popular test prep that says Ethanoic acid and Benzyl alcohol won't form Ethyl Benzoate, why? I thought it should also. Is it an error?

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[americanpierg]

I know Benzoic acid and Ethanol can form Ethyl Benzoate. There's a problem in one of the popular test prep that says Ethanoic acid and Benzyl alcohol won't form Ethyl Benzoate, why? I thought it should also. Is it an error?

you are rushing through this one. you have to remember that an alcohol and an acid makes an ester, but the acid has the double bonded oxygen in the ester, and gets the "-oate" designation. if you add benzyl alcohol and ethanoic acid, you would get benzyl ethanoate. the acid always loses its OH and the alcohol loses the other H to make H2O, and naming of the ester keeps the portion with the double bond as the parent name (in this case coming from the acid).

 

[wantVCUdental]

To the open poster, i think the reason why you can't put phenol with ethanoic acid is that in the transition state, there are 3 Oxygens connected to 1 carbon, and when the electrons kick back from the oxygen to push out the -OH group, the benzyl alcohol is a much better and stable leaving group, and so it'll kick the phenol off... so you still have the acid

while when you do the addition of ethanol+benzoic acid, the leaving groups are either water or ethanol, and those are equally stable...

Just my 2c

 

[lakers2009]

you are rushing through this one. you have to remember that an alcohol and an acid makes an ester, but the acid has the double bonded oxygen in the ester, and gets the "-oate" designation. if you add benzyl alcohol and ethanoic acid, you would get benzyl ethanoate. the acid always loses its OH and the alcohol loses the other H to make H2O, and naming of the ester keeps the portion with the double bond as the parent name (in this case coming from the acid).

I just drew out the structure and yea you are right. I had always thought it doesn't make any difference on ester starting reagents, but it does. Thanks for pointing that out.

PhCOO-Et is not same as MeCOO-CH2-Ph

 

[lakers2009]

To the open poster, i think the reason why you can't put phenol with ethanoic acid is that in the transition state, there are 3 Oxygens connected to 1 carbon, and when the electrons kick back from the oxygen to push out the -OH group, the benzyl alcohol is a much better and stable leaving group, and so it'll kick the phenol off... so you still have the acid

while when you do the addition of ethanol+benzoic acid, the leaving groups are either water or ethanol, and those are equally stable...

Just my 2c

It wasn't Phenol. It was Benzyl alcohol. They're not the same. I don't think transition has anything to do with it. It was just the outcome is different thus gets a different name than what superficially thought to be the same. Even if with Phenol & EtCOOH, I still think you can still get something but it won't be the same still. You'd get Phenyl Ethanoate. Thanks for the effort though. 🙂