A hydrocarbon `C_(9) H_(10) (A)` rapidly decolourises cold aquous permanganate and rapidly absorts one molecule of bromine . Vigous hydrogenation of `(A)` gives a compound `(A)` gives a compound `(B)` of the formula `C_(9) H_(18)`. Strong oxidation of `(A)` yileds phyalic acid. Propose a structure for `(A)` and give the basic for your answer.

Explanation

`D.U` in `(A) = ((2n_(C) +2) - n_(H))/(2) = ((9xx2+2)-10)/(2) = 5^(@)`
`5 D.U` in suggests benzene ring with me one `(C = C)` bond in the side chain. The presence of double bond in shown by decolourisation of cold alk. `KMnO_(4)` solutobn and reaction with `Br_(2)`.
Oxidation of `(A)` to phtalic acid suggests that one `(Me)` group and `(CH_(2) = CH -)` group are at ortho-positon.
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