Q67E - Organic Chemistry (Mcmurry)

Question

What condensation products would you expect to obtain by treatment of the following substances with sodium ethoxide in ethanol?

 

(a) Ethyl butanoate 

(b) Cycloheptanone

(c) 3,7-Nonanedione 

(d) 3-Phenylpropanal

 

Step-by-Step Solution

Answer

Condensation products after treatment of the following substances with sodium ethoxide in ethanol are given below.

Answer of subpart (a): Product of the reaction

Condensation product of ethyl butanoate with sodium ethoxide in ethanol is

Solution of the problem

The full reaction of ethyl butanoate with sodium ethoxide in ethanol is

Explanation of the solution

Ethyl butanoate has two α-hydrogens, hence it can participate in Claisen condensation reaction. Therefore, in treatment of two molecules of ethyl butanoate with sodium ethoxide in ethanol, it gives β-keto ester. 

Answer of subpart (b): Product of the reaction

Condensation product of cycloheptanone with sodium ethoxide in ethanol is

Solution of the problem

The full reaction of cycloheptanone with sodium ethoxide in ethanol is

Explanation of the solution

Cycloheptanone has α-hydrogens, hence it can participate in aldol condensation reaction. Therefore, in treatment of two molecules of cycloheptanone with sodium ethoxide in ethanol, it gives α,β-unsaturated ketone. 

Answer of subpart (c): Product of the reaction

Condensation product of 3,7-nonanedione with sodium ethoxide in ethanol is

Solution of the problem

The full reaction of 3,7-nonanedione with sodium ethoxide in ethanol is

Explanation of the solution

3,7-nonanedione has α-hydrogens, hence it can participate in intermolecular aldol condensation reaction. Therefore, in treatment of two molecules of 3,7-nonanedione with sodium ethoxide in ethanol, it gives α,β-unsaturated ketone. 

Answer of subpart (d): Product of the reaction

Condensation product of 3-phenylpropanal with sodium ethoxide in ethanol is

Solution of the problem

The full reaction of 3-phenylpropanal with sodium ethoxide in ethanol is

Explanation of the solution

3-phenylpropanal has α-hydrogens, hence it can participate in aldol condensation reaction. Therefore, in treatment of two molecules of 3-phenylpropanal with sodium ethoxide in ethanol, it gives α,β-unsaturated ketone.