Question 13.7: From what two different alkenes can 2-chloro-3-methylbutane ...
From what two different alkenes can 2-chloro-3-methylbutane be made?
\underset{\text{2-Chloro-3-methylbutane}}{ \begin{matrix} CH_3\,\,\,\,\,\, \\ CH_3\overset{|}{C}H{\underset{|}{C} } HCH_3 \\ \,\,Cl \end{matrix} }
ANALYSiS 2-Chloro-3-methylbutane is an alkyl chloride that might be made by addition of HCl to an alkene. To generate the possible alkene precursors, remove the —Cl group and an —H atom from adjacent carbons and replace with a double bond.
Look at the possible alkene addition reactions to see which is compatible with Markovnikov’s rule. In this case, addition to 3-Methylbut-1-ene is compatible. Note that if HCl is added to 2-Methylbut-2-ene, the major product will have the Cl attached to the wrong carbon (the carbon with the methyl group on it).
\underset{\text{3-Methylbut-1-ene}}{\begin{matrix} CH_3 \qquad\\ CH_3\overset{|}{C} HCH=CH_2 \end{matrix}} + HCl\longrightarrow \underset{\text{2-Chloro-3-methylbutane}}{ \begin{matrix} CH_3\,\,\,\,\,\, \\ CH_3\overset{|}{C}H{\underset{|}{C} } HCH_3 \\ \,\,Cl \end{matrix} }