Formation of carboxylate ester. What donates what?

Question

In the formation of a carboxylate ester from a carboxylic acid and an alkanol - which molecule donates what?

Does the alkanoic acid donate the hydroxyl (OH) group and the alkanol the hydrogen? Or does it depend on chain length or other variables?

Please link me to a source or website w. further explanation, that would be great!

Answer 1

You are correct. A lone pair of electrons on the O of the alcohol attacks the C of the carbonyl (C=O) group on the carboxylic acid (this is a bit complicated and involves an intermediate, but I have a link for you to look at), kicking off the OH from the carboxylic acid which then teams up with the H from the alcohol to form water.

esters are named alkyl alkanoates. The alkyl comes from the parent alkanol and the alkanoate comes from the alkanoic acid.

So for ethanol + propanoic acid = ethyl propanoate + water

http://www.ausetute.com.au/esters.html

http://en.wikipedia.org/wiki/Fischer_est...

http://www.chemguide.co.uk/physical/cata...

http://www-personal.une.edu.au/~sglover/...