Question

What is the main product of the reaction between 2-Methylpropene with HBr?

Options

• 1-Bromobutane

• 1-Bromo-2-methylpropane

• 2-Bromobutane

• 2-Bromo-2-methylpropane

Answer 1

2-Bromo-2-methylpropane

Explanation:

\[\begin{array}{cc}
\phantom{...........}\ce{Br}\\
\phantom{..........}|\\
\ce{CH3 - C = CH2 + HBr ->[Markovnikov's][rule] CH3 - C - CH3 + CH3 - CH - CH2 - Br}\\
\phantom{.}|\phantom{....................................}|\phantom{..................}|\phantom{........}\\
\phantom{}\ce{\underset{2-Methylpropene}{CH3}}\phantom{.....................}\ce{\underset{\underset{(Major product)}{2-Bromo-2-methylpropane}}{CH3}}\phantom{.}\ce{\underset{\underset{(Minor product)}{1-Bromo-2-methylpropane}}{CH3}}\phantom{.}
\end{array}\]