The tertiary glycols are known as pinacones and are formed on the reduction of ketones with sodium amalgam.
Taking as types hydrogen, hydrochloric acid, water and ammonia, he postulated that all organic compounds were referable to these four forms: the hydrogen type included hydrocarbons, aldehydes and ketones; the hydrochloric acid type, the chlorides, bromides and iodides; the water type, the alcohols, ethers, monobasic acids, acid anhydrides, and the analogous sulphur compounds; and the ammonia type, the amines, acid-amides, and the analogous phosphorus and arsenic compounds.
Thio-aldehydes, thio-ketones and thio-acids also exist.
By the action of hydroxylamine or phenylhydrazine on aldehydes or ketones, condensation occurs between the carbonyl oxygen of the aldehyde or ketone and the amino group of the hydroxylamine or hydrazine.
Experience has shown that such mono-derivatives as nitro compounds, sulphonic acids, carboxylic acids, aldehydes, and ketones yield as a general rule chiefly the meta-compounds, and this is independent of the nature of the second group introduced; on the other hand, benzene haloids, amino-, homologous-, and hydroxy-benzenes yield principally a mixture of the orthoand para-compounds.
Thus in the normal fatty alcohols, acids, esters, nitriles and ketones, the increment per CH 2 is 19°-21°; in the aldehydes it is 26°-27°.
This is true of the fatty acid series, and the corresponding ketones and alcohols, and also of the succinic acid series.
The same difference attends the introduction of the methyl group into many classes of compounds, for example, the paraffins, olefines, acetylenes, aromatic hydrocarbons, alcohols, aldehydes, ketones and esters, while a slightly lower value (157.1) is found in the case of the halogen compounds, nitriles, amines, acids, ethers, sulphides and nitro compounds.
It is remarkable that the difference in the heats of formation of ketones and the paraffin containing one carbon atom less is 67.94 calories, which is the heat of formation of carbon monoxide at constant volume.
OXIMES, in organic chemistry, compounds containing the grouping > C: N OH, derived from aldehydes and ketones by condensing them with hydroxylamine.
Those derived from aldehydes are known as aldoximes, those from ketones as ketoximes.
Beckmann, Ber., 1886, 1 9, p. 9 8 9; 188 7, 20, p. 2580), yielding as final products an acid-amide or anilide, thus: RC(:N OH)R'-RC(OH) :NR' ---> As regards the constitution of the oximes, two possibilities exist, namely >C: NOH, or > C' ?, and the first of these is presumably correct, since on alkylation and subsequent hydrolysis an alkyl hydroxylamine of the type NH 2 OR is obtained, and consequently it is to be presumed that in the alkylated oxime, the alkyl group is attached to oxygen, and the oxime itself therefore contains the hydroxyl group. It is to be noted that the oximes of aromatic aldehydes and of unsymmetrical aromatic ketones frequently exist in isomeric forms. This isomerism is explained by the HantzschWerner hypothesis (Ber., 1890, 23, p. II) in which the assumption is made that the three valencies of the nitrogen atom do not lie in the same plane.
Wallach (Ann., 1900, 312, p. 171) has shown that the saturated cyclic ketones yield oximes which by an application of the Beckmann reaction are converted into isoximes, and these latter on hydrolysis with dilute mineral acids are transformed into acyclic amino-acids; thus from cyclohexanone, e-amidocaproic acid (e-leucine) may be obtained: CH2" C NOH C CH 2 CH 2 7: ?12?CH2 CH2 NH /CH2 CH2 C02H CH2', An ingenious application of the fact that oximes easily lose the elements of water and form nitriles was used by A.
They are prepared by condensing thio-amides with a-haloid ketones or aldehydes, the thio-amide reacting as the tautomeric thio-imino acid.
Amino derivatives similarly result from thio-ureas and a-haloid ketones; the oxy derivatives from a-sulphocyanoketones by the action of caustic alkali; and the carboxylic acids from chloro-aceto-acetic ester, &c. and thioamides.
In organic chemistry, his study of the ketones and aldehydes, begun in 1857, provided him with the subject of his other doctoral thesis.
Sugar of lead, but it is now restricted to certain oxyaldehydes and oxy-ketones, which occur in the vegetable and animal kingdoms either free or in combination as glucosides (q.v.) and to artificial preparations of similar chemical structure.
Wallach, Ber., 1881, 14, P. 421); by the action of reducing agents on nitroparaffins; by the action of zinc and hydrochloric acid on aldehyde ammonias (German Patent 73,812); by the reduction of the phenylhydrazones and oximes of aldehydes and ketones with sodium amalgam in the presence of alcohol and sodium acetate (J.
Ketones, secondary alcohols and tertiary alcohols yield a mixture of acids on oxidation.
The calcium salts distilled with calcium formate yield aldehydes r distilled with soda-lime, ketones result.
It condenses with aldehydes and ketones to produce semioxamazones.
It combines with aldehydes and ketones to form the nitriles of oxy-acids, for example, CH 3 CHO+HCN=CH 3 CH(OH)(CN).
Nitriles yield ketones (the nitrogen being eliminated as ammonia), the best yields being given by the aromatic nitriles (E.
Acid amides also react to form ketones (C. Beis, ibid., 1903, 1 37, 575): R Conh 2 - E Rr' :C(OMgX) NHMgX R'H--R CO.
KETONES, in chemistry, organic compounds of the type R CO R', where R, R' = alkyl or aryl groups.
The ketones are of neutral reaction, the lower members of the series being colourless, volatile, pleasant-smelling liquids.
The ketones react with mercaptan to form mercaptols (E.
With nitrous acid (obtained from amyl nitrite and gaseous hydrochloric acid, the ketone being dissolved in acetic acid) they form isonitroso-ketones, R CO CH:NOH (L.
The -y-diketones are characterized by the readiness with which they yield furfurane, pyrrol and thiophene derivatives, the furfurane derivatives being formed by heating the ketones with a dehydrating agent, the thiophenes, by heating with phosphorus pentasulphide, and the pyrrols by the action of alcoholic ammonia or amines.
These compounds generally behave as ketones; but at the same time they may act as alcohols, i.e.
Villiger (Be y ., 1901, 34, pp. 2679, 3612) showed that many organic compounds (ethers, alcohols, aldehydes, ketones, &c.) behave towards acids, particularly the more complex acids, very much like bases and yield crystallized salts in which quadrivalent oxygen must be assumed as the basic element.
They combine with aldehydes and ketones, with elimination of water and formation of mercaptals and mercaptols.
The thiophen ketones may be prepared by the interaction of thiophen and its homologues with acid chlorides in the presence of anhydrous aluminium chloride.
The aldehydes and ketones provided material for his earlier work.
He observed that aldehydes and ketones may suffer reduction in neutral, alkaline, and sometimes acid solution to secondary and tertiary glycols, substances which he named pinacones; and also that certain pinacones when distilled with dilute sulphuric acid gave compounds, which he named pinacolines.
Secondary alcohols yield ketones, which are subsequently oxidized to a mixture of two acids.
Tertiary alcohols yield neither aldehydes nor ketones, but a mixture of two or more acids.
Secondary alcohols result from the reduction of ketones; and from the reaction of zinc alkyls on aldehydes or formic acid esters.
With aldehydes and ketones it forms oximes.
TERPENES, in organic chemistry, the generic name of a group of hydrocarbons of the general formula (C 5 H 8) n, and the more important oxygen derivatives, mainly alcohols, aldehydes and ketones, derived from them.
Alcohols are obtained from the corresponding halogen compounds by the action of moist silver oxide, or by warming them with silver acetate and acetic acid; by the reduction of ketones with metallic sodium; by passing the vapours of monohydric phenols and hydrogen over finely divided nickel (P. Sabatier and J.
Aldehydes and Ketones.-The aldehydes are prepared in the usual manner from primary alcohols and acids.