Question

Which of the following ketone will NOT give enamine on treatment with secondary amines? [where t-Bu is –C(CH3)3]

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

Answer 2

In order to form enamine from the reaction of carbonyl compound with 2º amine, the carbonyl compound must have α-hydrogen.

In above figure, there is no α-hydrogen is present.
Along with this, due to steric crowding by t-Bu group, it is difficult for 2º amine to attack on this compound.

So, the correct option is (C).