(N/A) Methyl ketones $(R-CO-CH_3)$ are oxidized by sodium hypohalite $(NaOX)$ to the sodium salts of corresponding carboxylic acids having one carbon atom less than that of the carbonyl compound. The methyl group is converted to haloform $(CHX_3)$. This oxidation does not affect a carbon-carbon double bond $(C=C)$,if present in the molecule.
$R-CO-CH_3 + 3NaOX \rightarrow R-COONa + CHX_3 + 2NaOH$
The reaction proceeds in two steps:
$(i)$ $R-CO-CH_3 + 3NaOX \rightarrow R-CO-CX_3 + 3NaOH$
(ii) $R-CO-CX_3 + NaOH \rightarrow R-COONa + CHX_3$
Iodoform reaction with sodium hypoiodite $(NaOI)$ is also used for the detection of the $CH_3CO-$ group or $CH_3CH(OH)-$ group,which produces iodoform ($CHI_3$,yellow precipitate) on oxidation.