Question

How are the following compound obtained by hydration of alkenes?

tert-butyl alcohol

Answer 1

2-Methylpropene (isobutylene) directly reacts with 50% H₂SO₄ giving tert-butyl hydrogen sulphate, which when heated with water gives tert-butyl alcohol.

\[\begin{array}{cc}
\ce{CH3}\phantom{........................}\ce{CH3}\phantom{...}\\
||\phantom{...........................}|\phantom{......}\\
\ce{CH3 - C + \underset{(50\%)}{HO - SO3H} -> CH3 - C - O - SO3H}\\
|\phantom{............................}|\phantom{......}\\
\phantom{..}\ce{\underset{(Isobutylene)}{\underset{2-Methylpropene}{CH3}}}\phantom{............} \ce{\underset{tert-Butyl hydrogen sulphate}{CH3}}
\end{array}\]

\[\begin{array}{cc}
\ce{CH3}\phantom{..............................}\ce{CH3}\phantom{.......}\\
|\phantom{..................................}|\phantom{.........}\\
\ce{CH3 - C - O - SO3H + H2O ->[heat] CH3 - C - OH + H2SO4}\\
|\phantom{..................................}|\phantom{.........}\\
\ce{CH3}\phantom{..........................}\ce{\underset{tert-Butyl alcohol}{CH3}}\phantom{..}
\end{array}\]