A hydrocarbon `A` of the molecular formula `C_8 H_10`. On ozonolysis gives only the compound `B(C_4 H_6 O_2)`. The compound `B` can also be obtained from the alkyl bromide `C(C_3 H_5 Br)` upon treatment with `Mg` in dry ether followed by the addition of `CO_2` and acidification. Identify `A, B` and `C` and also give equations for the reactions.

Explanation

`DU i n (A) = ((2n_C +2)-n_H)/(2) =((2 xx 8+2)-10)/(2) = 4^@`
`DU i n (B) = ((2n_C +2)-n_H)/(2) =((2 xx 4 +2)-6)/(2) = 2^@`.

Structure of B : Two `DU` in `(B)` means `1 DU` to `(-COOH)` group and `1 DU` due to `3C-ring, 1DU` due to the `(C=C)` bond is not possible because after ozonolysis, the `(C=C)` bond is never left behind). So the structure of `(B)` is
Structure of A : A is an 8-C atom compound and `(B)` is a 4-C-atom compound. So `2 mol` of `(B)` is obtained from the oxidative ozonolysis of `(A)`. Since an acid can be obtained only after oxidative ozonolysis, so the structure of `(A)` is
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