$(1)$ $\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\, \\
{{H}_{3}}C-C-C{{H}_{2}}-Cl \\
\end{matrix}$
$(2)$ ${{H}_{2}}C-C{{H}_{2}}-C{{H}_{2}}-Cl$
$(3)$ ${{({{H}_{3}}C)}_{3}}C-Cl$
$\left( C _6 H _5\right)_3 C - Cl \frac{ OH ^{-}}{\text {Pyridine }}\left( C _6 H _5\right)_3 C - OH$