Duclaux found that acetic acid is formed in small quantities during fermentation; aldehyde has also been detected.
According to this theory a " chemical type " embraced compounds containing the same number of equivalents combined in a like manner and exhibiting similar properties; thus acetic and trichloracetic acids, aldehyde and chloral, marsh gas and chloroform are pairs of compounds referable to the same type.
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.
4]-trimethylbenzene or pseudocumene; and of the condensation product of two molecules of isovaleryl aldehyde with one of acetone, C 3 H 7 CH 2 CH:C(C 3 H 7) CH:CH CO.
5]- ethylisophthalic acid, and with butyric aldehyde the corresponding propylisophthalic acid.
Torray's observations on nitromalonic aldehyde, N02 CH(CHO)2,formed by acting on mucobromic acid, probably CHO CBr:CBr:000H, with alkaline nitrites; this substance condenses with acetone to give p-nitrophenol, and forms [I.3.5]-trinitrobenzene when its sodium salt is decomposed with an acid.
The thermal effect of the aldehyde group has the average value 64.88 calories, i.e.
It is equal to the sum of the thermal effects of the aldehyde and carbonyl groups.
Thiele (Ber., 1905, 3 8, p. 4 1 54) from (-chlorpropionic aldehyde diethyl acetal.
Normal butyl alcohol, CH 3 (CH 2) 2 CH 2 OH, is a colourless liquid, boiling at 116.8°, and formed by reducing normal butyl aldehyde with sodium, or by a peculiar fermentation of glycerin, brought about by a schizomycete.
They are hydrolysed by dilute mineral acids yielding hydroxylamine and the parent aldehyde or ketone.
HO N Aldoximes are generally obtained by the action of hydroxylamine hydrochloride on the aldehyde in presence of sodium carbonate; the oxime being then usually extracted from the solution by ether.
YXiKis, sweet), a carbohydrate of the formula C 6 H 12 0 6; it may be regarded as the aldehyde of sorbite.
The aldehyde group reacts with hydrocyanic acid to produce two stereo-isomeric cyanhydrins; this isomerism is due to the conversion of an originally non-asymmetric carbon atom into an asymmetric one.
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.
When this compound is acted on by water, hydrogen peroxide and levulinic aldehyde are formed, the aldehyde being subsequently oxidized by the hydrogen peroxide, forming levulinic acid.
These esters on hydrolysis yield the free acids, which readily decompose, with loss of carbon dioxide and formation of an aldehyde, R /Crri /Crri Oc< +ï¿½Cl ï¿½ CH ï¿½ [[Cooc H - O I ?Ch Cooc H 0c Chï¿½Cooh - Co +Chrr I Cho]].
In the German Patent 1 57573 (1904) it is shown that by the action of at least two molecular proportions of an alkyl formate on two molecular proportions of a magnesium alkyl or aryl haloid, a complex addition compound is formed, which readily decomposes into a basic magnesium salt and an aldehyde, C H MgBr-f-H000R-ROï¿½CHï¿½C H.
They form many addition compounds, combining with ammonia to form aldehyde ammonias of the type R.
The hydrazones are best prepared by mixing the aldehyde with phenylhydrazine in dilute acetic acid solution, in the absence of any free mineral acid.
Briihl) and boiling point 104° C. Dilute acids readily transform it into alcohol and aldehyde, and chromic acid oxidizes it to acetic acid.
Aldehyde ammonia, CH 3.
With ammonia, benzaldehyde does not form an aldehyde ammonia, but condenses to hydrobenzamide, (C 6 H 5 CH) 3 N 2, with elimination of water.
Cumic aldehyde (cuminol), (CH 3) 2 CH(1) C 6 H.
Salicylic aldehyde (ortho-hydroxybenzaldehyde), HO(I)ï¿½ C 6 H 4 ï¿½CHO(2), an aromatic oxyaldehyde, is a colourless liquid of boiling point 196° C. and specific gravity.
Cinnamic aldehyde ((3-phenyl acrolein), C6H5ï¿½CH: CHï¿½CHO, an unsaturated aromatic aldehyde, is the chief constituent of cinnamon oil.
Fischer); by heating salicylic aldehyde with aniline and zinc chloride to 260° C. (R.
He prepared the cyanhydrins of glucose and fructose, hydrolysed them to the corresponding oxy-acids, from which the hydroxy groups were split out by reduction; it was found that glucose yielded normal heptylic acid and fructose methylbutylacetic acid; hence glucose is an aldehyde alcohol, CH 2 OH (CH OH) 4 CHO, whilst fructose is a ketone alcohol CH 2 OH (CH OH) 3 CO.
Glycerin appears to yield, on mild oxidation, an aldehyde, CH20H CH(OH) CHO, and a ketone, CH 2 OH CO CH 2 OH, and these condense as shown in the equation: CH 2 OH CH (OH) CHO + CH 2 OH [[Coch 2 Oh = Ch20h Ch(Oh) Ch(Oh) Ch(Oh) Co.Ch20h+H20]].
The identity of the formulae and osazones of d-mannose and d-glucose showed that the stereochemical differences were situated at the carbon atom adjacent to the aldehyde group. Fischer applied a method indicated by Pasteur in converting dextro into laevo-tartaric acid; he found that both d-mannonic and d-gluconic acids (the latter is yielded by glucose on oxidation) were mutually convertible by heating with quinoline under pressure at 140°.
- The only possible biose is glycollic aldehyde, CHO.CH20H, obtained impure by Fischer from bromacetaldehyde and baryta water, and crystalline by Fenton by heating dihydroxymaleic acid with water to 60°.
The trioses are the aldehyde and ketone mentioned above as oxidation products of glycerin.
Glyceric aldehyde, CH 2 OH CH(OH) CHO, was obtained pure by Wohlon oxidizing acrolein acetal, CH 2 CH(OC 2 H 5) 21 and hydrolysing.
Impure inactive forms result on the polymerization of glycollic aldehyde and also on the oxidation of erythrite, a tetrahydric alcohol found in some lichens.
Employing the notation in which the molecule is represented vertically with the aldehyde group at the bottom, and calling a carbon atom+or - according as the hydrogen atom is to the left or right, the possible configurations are shown in the diagram.
Chemically they appear to be ether anhydrides of the hexoses, the union being effected by the aldehyde or alcohol groups, and in consequence they are related to the ethers of glucose and other hexoses, i.e.
Dumas, who regarded them as hydrates of olefiant gas (ethylene); on the other they yielded chloroform, chloral and aldehyde, as well as other compounds of less general interest, and also the method of forming mirrors by depositing silver from a slightly ammoniacal solution by acet aldehyde.
J.C.S., 1902, 1, p. 555), who made the free base an aldehyde, but the salts of an iso-quinolinium type.
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.
Oxy-acids are carboxylic acids which also contain a hydroxyl group; similarly we may have aldehyde-acids, ketone-acids, &c. Since the more important acids are treated under their own headings, or under substances closely allied to them, we shall here confine ourselves to general relations.
Fittig and his pupils (Annalen, 1883, 216, pp. loo, 115; 1885, 227, pp. 55, 119), in which it was shown that the aldehyde forms an addition compound with the sodium salt of the fatty acid, and that the acetic anhydride plays the part of a dehydrating agent.
Crotonic acid, so named from the fact that it was erroneously supposed to be a saponification product of croton oil, may be prepared by the oxidation of croton-aldehyde, CH3 CH:CH CHO, obtained by dehydrating aldol, or by treating acetylene successively with sulphuric acid and water; by boiling allyl cyanide with caustic potash; by the distillation of 0-oxybutyric acid; by heating paraldehyde with malonic acid and acetic acid to, oo C. (T.
It possesses all the characteristic properties of an aldehyde; being readily oxidized to benzoic acid; reducing solutions of silver salts; forming addition products with hydrogen, hydrocyanic acid and sodium bisulphite; and giving an oxime and a hydrazone.
The first compound, containing a group COH, or more explicitly 0 = CH, is an aldehyde, having a pronounced reducing power, producing silver from the oxide, and is therefore called propylaldehyde; the second compound containing the group - C CO C - behaves differently but just as characteristically, and is a ketone, it is therefore denominated propylketone (also acetone or dimethyl ketone).
The phenomena were first observed without mutual transformation, aldehyde melting at - 118°, paraldehyde at 13°, the only mutual influence being a lowering of melting-point, with a minimum at - 120° in the eutectic point.
Synthetically prepared by the reduction of benzoyl chloride; by the action of nitrous acid on benzylamine; by boiling benzyl chloride with an aqueous solution of potassium carbonate, or by the so-called "Cannizzaro" reaction, in which benzaldehyde is shaken up with caustic potash, one half of the aldehyde being oxidized to benzoic acid, and the other half reduced to the alcohol.
It consists essentially of cinnamic aldehyde, and by the absorption of oxygen as it becomes old it darkens in colour and develops resinous compounds.
With aromatic hydrocarbons in the presence of anhydrous aluminium chloride, in the cold, there is a large evolution of hydrochloric acid gas, and an aldehyde is formed; at 100° C., on the other hand, anthracene derivatives are produced.
When mesitylene is used, the reaction does not proceed beyond the aldehyde stage since hydrocarbon formation is prevented by the presence of a methyl group in the ortho-position to the -CHO group. Acids and alkalis are in general without action on nickel carbonyl.
It has been suggested that urea is formed by polymerization of ammonium carbonate, and formic aldehyde is synthesized from CO 2 and 011 2.
The oxidation of the alcohol leading to the formation of aldehyde and water, and the further oxidation of the aldehyde to acetic acid.
He studied the formation of aldehyde from alcohol by various methods, also obtaining its crystalline compound with ammonia, and he was the discoverer of furfurol.
Hantzsch (Ann., 1882, 215, p. I; Ber., 1882, 15, p. 2914) which consists in the condensation of two molecules of aceto-acetic ester with one of an aldehyde and one of ammonia: RO 2 C CH 2 R' CHO CH 2 CO 2 R RO 2 C C CHR' C C02R CH 3 CO + NH 3 + CO CH 3 -' CH3 C-NH-C CH3 The resulting dihydro-compound is then oxidized with nitrous acid, the ester hydrolysed and the resulting acid heated with lime; carbon dioxide is eliminated and a trisubstituted pyridine of the type CH C(CH3) is obtained.
In this reaction the proportions of aldehyde and acetoacetic ester may be interchanged and ay disubstituted pyridines are then obtained.
The carbon disulphide and salicylic aldehyde products have also been used as means of distinction, as has also the formation of the stilbazonium bases obtained by condensing ortho-semidines with benzil (0.
The reaction is a perfectly general one, for the aniline may be replaced by other aromatic amines and the aldehyde by other aldehydes, and so a large number of quinoline homologues may be prepared in this way.
Riiber (Ber., 1902, 35, p. 2411; 1904, 37, P. 22 74), by oxidizing diphenyl-2.4-cyclo-butane-bismethylene malonic acid (fron cinnamic aldehyde and malonic acid in the presence of quinoline) with potassium permanganate.
In organic chemistry, a celebrated example is Cannizzaro's reaction wherein an aromatic aldehyde gives an acid and an alcohol: 2C E H 5 CHO+H 2 O =C6H5C02H+C6H5CH20H.
Oxidation by strong oxidizing agents converts it successively into its aldehyde, acrolein, and into acrylic acid.