Q23-12P
Question
As shown in Figures 23-4, the Claisen reaction is reversible. That is, a 𝛃-keto ester can be cleaved by base into two fragments. Using curved arrows to indicate electron flow, show the mechanism by which this cleavage occurs.
Step-by-Step Solution
Verified Answer
When a 𝛃-keto ester reacts with a strong base (NaOH) it can give us two products but one of them is reversible and can’t give the desired product.
1Base (NaOH) can be attacked at two positions of 𝛃-keto ester:
a. When the base (-OH) is attacked at acidic 𝛂-hydrogen the reaction will reverse easily and we can’t get the desired product.
b. But when (-OH) is attacked at the carbon of the carbonyl group, then the reaction is irreversible and we can easily get the desired product.
2Cleavage of the 𝛃-keto ester by base like NaOH:
The required reaction is:
Other exercises in this chapter
Q11P
Show the products you would expect to obtain by Claisen condensation of the following esters: (a) CH3CHCH2CO2Et (b) Ethyl phenylacetate (c) Ethyl cyclohexy
View solution Q12P
As shown in Figures 23-4, the Claisen reaction is reversible. That is, a 𝛃-keto ester can be cleaved by base into two fragments. Using curved arrows to in
View solution Q23-11P
Show the products you would expect to obtain by Claisen condensation of the following esters: (a) (CH3)2CHCH2CO2Et (b) Ethyl phenylacetate (c
View solution Q13P
What product would you expect from the following mixed Claisen-like reaction?
View solution