Question

Is it possible to oxidise t-butyl alcohol using acidified dichromate to form a carbonyl compound?

Answer 1

3° alcohols do not undergo oxidation reaction under normal conditions, but at elevated temperature, under strong oxidising agent cleavage of C-C bond takes place to give a mixture of carboxylic acid.

Yes, it is possible. t-butyl alcohol is readily oxidsing in acidic solution (K₂Cr₂O₇/H₂SO₄) to a mixture of a ketone and an acid each containing a lesser number of carbon atoms than the original alcohol. The oxidation presumably occurs via alkenes formed through dehydration of alcohols under acidic conditions.

\[\begin{array}{cc}
\phantom{..}\ce{CH3}\phantom{......................}\ce{CH3}\phantom{....}\ce{CH3}\phantom{.................................}\\
\phantom{.}|\phantom{..........................}|\phantom{...........}\backslash\phantom{..............................}\\
\ce{CH3 - C - OH ->[H^+/K2Cr2O7][-H2O] CH3 - C = CH2 ->[(O)] C = O + \underset{(Formic acid)}{HCOOH} ->[(O)] CO2 + H2O}\\
\phantom{}|\phantom{.....................................}/\phantom{..............................}\\
\phantom{..}\ce{\underset{({t}-butyl alcohol)}{CH3}}\phantom{........................}\ce{\underset{(Acetone)}{CH3}}\phantom{....................................}
\end{array}\]