question_answer

Compound A of molecular formula \[{{C}_{9}}{{H}_{7}}{{O}_{2}}Cl\] exists in ketoform and predominatly in enolic form B. On oxidation with \[KMn{{O}_{4}},\]   A gives m-chlorobenzoic acid. Identify A and B. 

A)

B)

C)

D)

Correct Answer: B

Solution :

\[\underset{(A)}{\mathop{{{C}_{9}}{{H}_{7}}{{O}_{2}}Cl}}\,\] exists in keto form and predominatly in enolic form must contain \[-\underset{\underset{O}{\mathop{\parallel }}\,}{\mathop{C}}\,-C{{H}_{{{2}^{-}}}}\]group

Oxidation of [A] gives m-chlorobenzoic add

\[{{C}_{9}}{{H}_{7}}{{O}_{2}}Cl\,\,(A)\xrightarrow[KMn{{O}_{4}}]{(O)}\]

Hence, the compound should have a skeleton struct.

Thus, A is