The Claisen Condensation
Give the major organic product for the mixed Claisen condensation reaction shown on the left. You should assume that ethyl formate (the reactant with no a-hydrogens) is present in excess.Click the mouse on the compound to view the answer;
click on the button to view the tetrahedral intermediate in the condensation reaction.
Ethyl acetate forms an enolate anion which attacks a molecule of ethyl formate (which is present in excess) to give the tetrahedral intermediate shown. Expulsion of ethoxide anion from this intermediate yields the b-keto ester.
In the presence of alkoxide, ethyl acetate will enolize and the enolate anion will attack a molecule of ethyl formate (which is present in excess) to give the tetrahedral intermediate shown above. Remember that this intermediate will break down by expelling ethoxide, to yield a b-keto ester.