Question

Which of the following compounds would you expect to undergo aldol self-condensation? Show the product of each successful reaction.

(a) Trimethyl acetaldehyde

(b) Cyclobutanone

(c) Benzophenone (diphenyl ketone)

(d) 3-Pentanone

(e) Decanal

(f) 3-Phenyl-2-propenal

Short answer

Aldol condensation occurs in those aldehydes and ketones which have acidic𝛂-hydrogen and on treatment with a base it gives𝛃-hydroxy aldehydes and ketones.

Step-by-step solution

(a)Trimethyl acetaldehyde 

Since it does not contain 𝛂-hydrogen therefore this compound does not give an aldol self-condensation reaction.

(b) Cyclobutanone

(c) Benzophenone (diphenyl ketone)      

Since the Benzophenone does not contain𝛂-hydrogen therefore this compound does not give an aldol self-condensation reaction.

(d) 3-Pentanone

(e) Decanal                                                          

(f) 3-Phenyl-2-propenal

3-Phenyl-2-propenal does not undergo aldol self-condensation since its𝛂-hydrogen is not acidic.