Looking for classes? Ksquare Career Institute, Bengaluru →
Claisen Condensation
Concepts tested here
- Condensation of esters
All Questions
2006 AIPMT-PRE 1 question
-
Self condensation of two moles of ethyl acetate in presence of sodium ethoxide yields :-Esters having $\alpha$-hydrogen atoms undergo self condensation in the presence of a strong base such as sodium ethoxide. This is the Claisen condensation.
The base removes an $\alpha$-hydrogen from one molecule of ethyl acetate to give a carbanion, $^-CH_2COOC_2H_5$.
The carbanion attacks the carbonyl carbon of a second molecule of ethyl acetate, and a molecule of ethanol is eliminated.
$CH_3-CO-OC_2H_5 + H-CH_2-CO-OC_2H_5 \xrightarrow{C_2H_5ONa} CH_3-CO-CH_2-CO-OC_2H_5 + C_2H_5OH$
The product is a $\beta$-keto ester, ethyl acetoacetate (ethyl 3-oxobutanoate), commonly called acetoacetic ester.
So the product is acetoacetic ester.