Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

Question Explanation:

Question is asking about the number of compound which can show keto enol tautomerism.

Concept:

This question is based on  tautomerism.

Solution :  

Keto–enol tautomerism  is a  dynamic equilibrium  between the  keto form  and the  enol form  of a carbonyl compound.

For this interconversion to occur, the compound must have at least  one α-hydrogen , either  directly attached  to the carbon adjacent to the carbonyl group or  indirectly attached  through  conjugation with a multiple bond .

If a carbonyl compound  lacks an α-hydrogen , it  cannot form the enol tautomer  and therefore  does not exhibit keto–enol tautomerism .

Compounds 1, 4, 6, and 9 do not contain any saturated α-hydrogen atoms; therefore, these compounds do not exhibit tautomerism