Consider that there may be other reactions also going on, not just acid-base chemistry. So, for instance in the Claisen reaction of ethyl acetate, if methoxide was used instead of ethoxide then you may get methyl acetate formed as well.
Consider that there may be other reactions also going on, not just acid-base chemistry. So, for instance in the Claisen reaction of ethyl acetate, if methoxide was used instead of ethoxide then you may get methyl acetate formed as well.
The Claisen condensation of ethyl acetate (pKa=~25) is usually conducted in concentrated EtONa/EtOH (pKa=~16) or EtONa in an inert solvent such as toluene. The product, ethyl acetoacetate (AAE; pKa=~11) , is deprotonated by the EtONa generated in the condensation. Unlike the aldol condensation, which is catalytic in base, the Claisen condensation must be conducted with stoichiometric base.More
Are there other advantages? I thought that formation of the alcohol and its successive ionisation (negligible, but non zero) in aqueous solution maybe a way of regenerating the catalyst so that the reaction is thereafter self sustaining. Is it true?More
This is NOT done in aqueous soln. If an ester group is part of the reaction then the leaving group is the alkoxide of the ester, this is how the alkoxide is regenerated.More
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