Thus with hydroxylamine aldehydes yield aldoximes, R CH: N OH, and ketones, ketoximes, R 2 C: N OH (see Oximes), while phenyl hydrazine gives phenylhydrazones, R 2 C:N NH C 6 H 5 (see Hydrazones).
The ketoximes by the action of acetyl chloride undergo a peculiar inframolecular re-arrangement known as the Beckmann trans formation (E.
Ketoximes are usually rather more difficult to prepare than aldoximes, and generally require the presence of a fairly concentrated alkaline solution.
In order to arrive at the configuration of the stereoisomeric ketoximes, A.
On the addition of phenylhydrazine it gives a phenylhydrazone, and with hydroxylamine furnishes an oxime C6H5.CH3.C=N.OH melting at S9°C. This oxime undergoes a peculiar rearrangement when it is dissolved in ether and phosphorus pentachloride is added to the ethereal solution, the excess of ether distilled off and water added to the residue being converted into the isomeric substance acetanilide, C6H5NHCOCH3, a behaviour shown by many ketoximes and known as the Beckmann change (see Berichte, 1886, 19, p. 988).
How would you define ketoximes? Add your definition here.