Write the major product of the following reaction:
(a) `CH_(2)=CHBr underset("alcohol")overset(AgCN)to`

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Explanation

(a) Since vinyl halides are unreactive towards nucleophilic substitution reactions, therefore, `CH_(2)=CHBr` does not react AgCN.
`CH_(2)=CHBr underset("alcohol")overset(AgCN)to`No reaction.
(b) The initially formed less stable `1^(@)` carbocation (I) undergoes 1,2-methyl shift to give the more stable `3^(@)` carbocation (II) which then attacks the benzene ring to give. F.C. alkylation product (III),

(c) The initially formed less stable `1^(@)` carbocation (I) undergoes rearrangement by 1,2-hydride shift to form more stable `3^(@)` carbocation (II) which then attacks the toluene ring at the less hindered p-position to form p-cymene.
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