It has occurred to me that it is very common see the use of basic conditions for ester hydrolysis in various syntheses. One such sequence commonly seen in the case of the malonic ester synthesis is:

  1. $\ce { OH^-,H2O}$

  2. $\ce {H^+, heat}$

The first step is for the hydrolysis while the second step is for the decarboxylation. It is strange that there is a first step with basic conditions since ester hydrolysis and decarboxylation can both take place in acidic solution. Are there practical reasons for why ester hydrolysis is done with aqueous base?

  1. Precedent - why change conditions that others have shown work well?

  2. Control - it is much easier to react 1 eq of base/nucleophile under mild conditions, whereas acid hydroysis generally requires excess reagent and higher temperatures.

  3. Ease of operation - base hydrolysis gives a carboxylic salt as product which frequently extracts into aq, giving an easy workup and purification. Acid hydrolysis requires neutralisation of excess reagent as a first step.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.