An oxime is a derivative of an aldehyde or a ketone (termed aldoxime and ketoxime,
respectively) formed by the condensation with hydroxylamine (NH2OH), and containing the group C=N–OH.
Being easily isolated and with characteristic melting
points, oximes are used in qualitative analysis for identification of
aldehydes and ketones. For example, acetaldehyde (ethanal) forms the aldoxime CH3CH=NOH, and acetone (propanone) forms the ketoxime (CH3)2C=NOH. Ketoximes
undergo the Beckmann rearrangement.