a
(a)\(\mathop {C{H_3} - \mathop {CH}\limits_{\mathop {{\kern 1pt} |{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} }\limits_{Br{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} } }  - \mathop {C{\text{ }} - {\text{ }}}\limits_{\,\,\,\mathop {|{\kern 1pt} {\kern 1pt} }\limits_{Br} \,\,\,\,\,\,\,\,\,\,{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} }^{\mathop {|{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} }\limits^{C{H_{3\,\,}}} \,\,\,\,\,\,\,} C{H_2} - C{H_3} + Zn \to }\limits_{{\text{2}},{\text{3}} - {\text{dibromo}} - {\text{3}} - {\text{methyl}}{\kern 1pt} {\text{pentane}}{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} } \)
\(\mathop {C{H_3} - CH = \mathop {C{\mkern 1mu}  - {\mkern 1mu} {\mkern 1mu} }\limits^{\mathop {|\,\,\,{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} }\limits^{C{H_{3\,\,\,}}} } C{H_2} - C{H_3} + ZnB{r_2}}\limits_{{\text{HI}}{\kern 1pt}  + {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\text{Red}}{\kern 1pt} {\text{P}}{\kern 1pt} \left( {{\text{Reduction}}} \right)} \)
\(\mathop {C{H_3} - C{H_2} - \mathop {CH{\mkern 1mu} {\mkern 1mu} }\limits_{\mathop {|{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} }\limits_{C{H_3}\,\,\,\,} }  - C{H_2} - C{H_3}}\limits_{{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\text{3}} - {\text{Methyl}}{\kern 1pt} {\text{pentane}}} \)