The aldehydes and ketones provided material for his earlier work.
Of such condensation products undoubtedly the most important are the hydrazones, which result from the interaction with aldehydes and ketones.
This has so far been proved with certainty for the fusel oil and succinic acid, and rendered highly probable for all the various aldehydes and acids of which traces have been detected.
Fusel oil would be formed by the reduction of the aldehydes arising from the simple monobasic amino-acids, succinic acid would be produced by oxidation of the aldehyde derived from the dibasic glutamic acid.
Further, the aldehydesso produced would readily pass by oxidation into the corresponding fatty acids, small quantities of which are invariably produced in fermentation.
Hantzsch has shown that aldehydes condense with aceto-acetic ester and ammonia to produce the homologues of pyridine, thus: R R | | ROOC.
The aldehydes may be prepared by the careful oxidation of primary alcohols with a mixture of potassium dichromate and sulphuric acid,--3R.
The aldehydes are characterized by their great chemical reactivity.
Secondary alcohols result from the reduction of ketones; and from the reaction of zinc alkyls on aldehydes or formic acid esters.
NH2, has also been employed for the identification of aldehydes (W.
The primary alcohols are first oxidized to aldehydes (q.
Unsaturated aldehydes are also known, corresponding to the olefine alcohols; they show the characteristic properties of the saturated aldehydes and can form additive compounds in virtue of their unsaturated nature.
Aldehydes are converted into resins by the action of caustic alkalies.
Tertiary alcohols yield neither aldehydes nor ketones, but a mixture of two or more acids.
In reality besides the extremely minute traces of grape-sugar, a whole number of aldehydes and ketones are present in urine, which can form phenylazone.
This preparation has the characteristic peculiarity of forming crystalline compounds with aldehydes and ketones.
The production of esters, as mentioned in Chapters IX and X, of various alcohols and aldehydes are activities which are sometimes of value in the study of bacteria, but need not be further discussed.
Condensation with Aldehydes By treating phenolsulphonic acid with acetaldehyde in the usual way, a viscous brown mass is obtained, which is very soluble in water, the solution being of a brown colour.
The reaction between phenols and aldehydes has been further studied by Michael, [Footnote: Amer.
Finally, it may be assumed that easily oxidizable substances, such as aldehydes and acids, are possibly protected against too rapid, or premature, oxidation by being transformed into glucosides.
OH, yield by oxidation aldehydesand are distinguished by the name primary; whereas those containing CH.
Pungent vapours are evolved in the drying operations, amongst which is acrolein and probably also other aldehydes, and it is thought by Procter that these aldehydes also are essential tanning agents and typical of the process (cf.
The precise action of the aldehydes is also as yet somewhat obscure, but it is noteworthy that very small proportions of formalin will give a complete tannage.
In addition to the lactic acid, there are produced traces of acetic, succinic, formic and proprionic acids, traces of certain alcohols, aldehydes and esters.
The large percentage of these acids, with comparatively large amounts of certain alcohols, aldehydes and esters, invariably impart undesirable flavors and odors to the milk.
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.
Though the non-aldehydes volatilize with difficulty, they are volatile, and hence the ether must be quickly expelled, and the beaker not allowed to stand longer upon the water-bath than necessary for the evaporation of the ether.
In his experiments he was guided by the following points: A series of volatile oils contains partially free organic acids, like oils of bitter almonds and cinnamon, and partially aldehydes or other combinations.
The weight of the non-aldehydes thus obtained is deducted from the cassia oil used, the difference giving the content of cinnamaldehyde in the latter.
The apparent mechanism for the production of amino acids is as follows: aldehydes and hydrogen cyanide are synthesized in the gas phase by the electrical discharge.
The flask is then filled with the sodium sulphite solution, the volume of the cooled unabsorbed oil read off, and the percentage of aldehydes calculated as before.
Rancidity of fats and oils is entirely due to oxidation, in addition to free acid, aldehydes and ketones being formed, and it has been proposed to estimate rancidity by determining the amount of these latter produced.
In the case of lemon oil, where the proportion of aldehydes, though of great importance, is relatively very small, it is necessary to first concentrate the aldehydes before determining them.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "aldehydes" in a variety of sentences. We hope that you will now be able to make sentences using this word.
