Geminal halide hydrolysis

Geminal halide hydrolysis is an organic reaction. The reactants are geminal dihalides with a water molecule or a hydroxide ion. The reaction yields ketones from secondary halides or aldehydes from primary halides.

Reaction mechanism

The first part of the reaction mechanism consists of an ordinary nucleophilic [aliphatic substitution ] to produce a gem-halohydrin:
The remaining halide is a good leaving group and this enables the newly created hydroxy group to convert into a carbonyl group by expelling the halide:

Variations

Other functional groups can undergo similar hydrolysis reactions. For instance, geminal trihalides can be partially hydrolyzed to acyl halides in a similar way. Further hydrolysis yields carboxylic acids.