Question

The major product obtained in the photo catalysed bromination of 2-methylbutane is ______.

विकल्प

• 1-bromo-2-methylbutane

• 1-bromo-3-methylbutane

• 2-bromo-3-methylbutane

• 2-bromo-2-methylbutane

Answer 1

The major product obtained in the photo catalysed bromination of 2-methylbutane is 2-bromo-2-methylbutane.

Explanation:

The order of substitution in different alkanes is:

3° > 2° > 1°

Thus, the bromination of 2-methylbutane mainly gives 2-bromo-2-methylbutane.

\[\begin{array}{cc}
\phantom{..........}\ce{CH3}\phantom{..........................}\ce{CH3}\phantom{........................}\ce{CH3}\phantom{.}\\
\phantom{........}|\phantom{.............................}|\phantom{............................}|\phantom{.}\\
\phantom{.}\ce{\underset{2-Methylbutane}{CH3 - CH2 - CH - CH3} ->[Br2] \underset{\underset{(minor)}{1-Bromo-2methylbutane}}{CH3 - CH2 - CH - CH2Br} + CH3 - CH2 - C - CH3}\\
\phantom{.................................................................}|\\
\phantom{..................................................................}\ce{\underset{\underset{(major)}{2-Bromo-2-methylbutane}}{Br}}\phantom{.}
\end{array}\]