Compounds containing the group - CH: O are known as aldehydes (q.v.), while the group >C: O (sometimes termed the carbonyl or keto group) characterizes the ketones (q.v.).
In general, the rupture occurs between a keto group (CO) and a keto-chloride group (CC1 2), into which two adjacent carbon atoms of the ring are converted by the oxidizing and substituting action of chlorine.
The aldehyde group also reacts with phenyl hydrazine to form two phenylhydrazones; under certain conditions a hydroxyl group adjacent to the aldehyde group is oxidized and glucosazone is produced; this glucosazone is decomposed by hydrochloric acid into phenyl hydrazine and the keto-aldehyde glucosone.
The keto-dihydrotriazoles or triazolones are obtained by the action of hydrazines on acetyl urethane (A.
It is found also that some monosaccharoses behave as aldehydes whilst others contain a keto group; those having the first character are called aldoses, and the others ketoses.
Those in which the keto groups are in combination with phenyl residues give pyridine derivatives on treatment with hydroxylamine, thus benzamarone, C 6 H 5 CH[CH(C 6 H 5) CO.
On oxidation .ith chromic acid it forms a quinone, C 15 H 8 0 2, and an a-diphenylene keto carboxylic acid C E I-4 3.
It undoubtedly contains a keto-group, for it reacts with hydrocyanic acid, hydroxylamine, phenylhydrazine and ammonia; sodium bisulphite also combines with it to form a crystalline compound, hence it contains the grouping CH 3 ï¿½CO-.
For a discussion as to the composition, and whether it is to be regarded as possessing the "keto" form CH3ï¿½COï¿½CH2ï¿½000C2H5 or the "enol" form CH 3 ï¿½C(OH): CHï¿½C00C 2 H 5, see Isomerism, and also papers by J.
Two classes may be distinguished: the aldo-ketenes, including ketene itself, together with its monoalkyl derivatives and carbon suboxide, and the keto-ketenes which comprise the dialkyl ketenes.
CH -CO CH2 from 1.5-diketones which contain a methyl group next the keto-group (W.
Attempts to eliminate water from this acid and so produce an unsaturated acid were unsuccessful; on warming with sulphuric acid, carbon monoxide is eliminated and cyclo-butanone (keto-tetramethylene) is probably formed.