Vapours of alcohol are passed over hot copper to give ketone. Ketone reacts with ethylene glycol to give a cyclic ketal. Cyclic ketal by treating with aq. HCl forms acetone. Identify the alcohol.

Step-by-step solution

The cyclic ketal on hydrolysis with aqueous HCl yields acetone. This indicates that the ketone formed in the first step is acetone ( CH₃COCH₃ ). When vapours of an alcohol are passed over hot copper at 573 K, secondary alcohols undergo dehydrogenation to form ketones. To form acetone, the starting alcohol must be a secondary alcohol with three carbon atoms. Propan-2-ol ( CH₃CH(OH)CH₃ ) on passing over hot Cu undergoes dehydrogenation to give acetone. Acetone reacts with ethylene glycol in the presence of dry HCl ga