question_answer

Write the major product of the following reactions : (a) \[C{{H}_{2}}=CHBr\,\xrightarrow[\text{alcohol}]{\text{AgCN}}\] (b)

Answer:

.                 (a) Since vinyl halides are unreactive towards nucleophilic substitution reactions, therefore, \[C{{H}_{2}}=CHBr\] does not react with \[AgCN\]. \[C{{H}_{2}}=CHBr\xrightarrow[\text{alcohol}]{\text{AgCN}}\text{No}\,\text{reaction}\] (b) The initially formed less stable \[1{}^\circ \] carbocation \[(I)\] undergoes 1, 2-methyl shift to give the more stable \[3{}^\circ \]carbocation \[(II)\]which then attacks the benzene ring to give. F.C. alkylation product \[(III),\]