[chrisso80b]

Hi  

Just wondering, what is the reasoning as to why acyl chlorides are the most reactive carboxylic acid derivative?
i.e. Why is it that the relative reactivities of carboxylic derivatives is:
acyl chloride > anhydride > ester > amide

Thanks!

[Honclbrif]

Did you read the chapter in your ochem text on carboxylic acids and their derivatives? It should be there.

[Dan]

See also: This (which was the second hit on google for carbonyl reactivity order)

[karbon]

Which of those groups are most electron withdrawing?

[Babcock_Hall]

I would analyze it in terms of the pKa of the conjugate acid of the leaving group.  Stronger bases make poorer leaving groups than weaker bases.  Chloride is a weaker base than acetate (which would be the leaving group in acetic anhydride).