[shelley]

Hi,

Can you please view my hand drawn and written trans-esterification rxn (attached file) to see if I have drawn and labelled their names correctly?  Thank you.

[discodermolide]

A transesterification reaction is also catalysed by base, usually the alkoxide of the alcohol you are using to make the new ester.

[gritch]

A transesterification reaction is also catalysed by base, usually the alkoxide of the alcohol you are using to make the new ester.

If memory serves, transesterification can be acid catalyzed as well. You should get pronotation of the carbonyl oxygen which creates an "electron sink" that is reactive enough for be attacked by the alcohol itself. Subsequent removal of the alcohol leaving group and depronotation should form the second ester. It's any equilibrium reaction but a large excess of the alcohol should drive it to completion.     

[discodermolide]

Read what I said, "also catalysed by base". Nowhere did I say it was not catalysed by acid.