Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: minimal on December 14, 2007, 11:36:43 AM
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They seem to be the same, or at least a carbonyl is an acyl but an acyl is not necessarily a carbonyl?
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Just terminology, the hydroxyl removed from a carboxylic acid can have any substituent R
ex. COOH --(SOCl2)--> COCl (Acyl halide)
http://en.wikipedia.org/wiki/Acyl
http://en.wikipedia.org/wiki/Carbonyl
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For that matter, what is the difference between using the -R or a -A or -B. Is a -A or -B a single group, whereas the -R could be anything, including continuing carbon chains?
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A or B can be anything and they can be different, it is the same as say R and R'
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A or B can be anything and they can be different, it is the same as say R and R'
Then why is the distinction made on something like wikipedia between the acyl and the carbonyl groups, where the carbonyl is listed with A & B, while the acyl has an -R group.
And secondly, does the acyl group imply that there is a negative charge? I notice that it does not list two R groups. And since an acyl is the removal of the hydroxyl group on a carboxylic acid, does that mean that it must end with the negative charge?
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Just different terminology but yes they can mean the same thing formally.
An acyl group is derived from a carboxylic acid. Anytime you add a RC=O to a heteroatom you are acylating that group. If any charge is present it is positive. The acyl carbocation is a common synthon.
http://en.wikipedia.org/wiki/Synthon
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Just different terminology but yes they can mean the same thing formally.
An acyl group is derived from a carboxylic acid. Anytime you add a RC=O to a heteroatom you are acylating that group. If any charge is present it is positive. The acyl carbocation is a common synthon.
http://en.wikipedia.org/wiki/Synthon
Great, thanks for the reference. However, I have another question after checking out that wiki page about Synthons. How do they determine that CN- is a synthetic equivalent for COOH-? Just because there is a similar carbanion? I understand that they get there in two steps (first the NaCN and then adding H20), but that really doesn't make CN- a synthetic equivalent unless you add the part about adding H20 correct? Unless I'm missing something. Wouldn't a synthetic equivalent be more like NaCOOH? instead of CN- and then H20?