question_answer

Tautomerism is not exhibited by

A)  

B)  

C)  

D)  

Correct Answer: A

Solution :

 For keto-enol isomerism a compound should have at least one \[\alpha -\]hydrogen atom with respect to ketone group or in other words for tautomerism presence of \[\alpha -\]hydrogen atom is essential,                               does not exhibited tautomerism due to absence of \[\alpha -\]hydrogen atom.