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[1][2] or aldehydes from primary halides.[3][4]
Reaction mechanism
The first part of the reaction mechanism consists of an ordinary nucleophilic aliphatic substitution to produce a gem-halohydrin:
- RCH(Cl)2 + KOH RCH(OH)Cl + KCl
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:
- RCH(OH)Cl Rearrangement gives R-CHO + HCl
Variations
Other functional groups can undergo similar hydrolysis reactions. For instance, geminal trihalides (e.g. benzotrichloride) can be partially hydrolyzed to acyl halides (e.g. benzoyl chloride) in a similar way.[5] Further hydrolysis yields carboxylic acids.