摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr31-013

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

A description is given of the properties of levan, a polysaccharide obtained by the action ofBacillus mesentericus, and of its enzyme, on sucrose; in particular, its complete hydrolysis to fructose, and behavior when subjected to acetylation and methylation.By hydrolysis of trimethyl levan, a crystalline trimethyl fructose was obtained (the first crystalline methylated γ-sugar to be synthesized). This yielded a trimethyl methylfructoside on condensation with methyl alcohol containing HCl. The properties of these compounds are described for the first time.On methylation and subsequent hydrolysis of the glucide, a tetramethyl fructose was obtained having properties identical with those of the tetramethyl fructose obtained by hydrolysis of heptamethyl sucrose.Oxidation of the new trimethyl fructose yielded a dibasic dimethyl lactol acid, and esterification of the latter, followed by methylation and treatment with dry ammonia, gave a crystalline diamide. These results show that the new crystalline trimethyl fructose is 1:3:4-trimethyl fructofuranose.It follows from this that levan is a polymerized anhydro-fructofuranose with linkages at positions 2 and 6 of the fructose chain, thus differing from inulin which has been shown to be an anhydro-fructofuranose with linkages at positions 1 and 2.The synthesis of levan thus represents a further example of the polymerization of an anhydro sugar taking place through the medium of the γδ hydroxyl groups. It serves to emphasize the importance of these spatial positions with reference to the carbonyl group, a phenomenon to which attention has been drawn repeatedly by Hibbert.

ISSN:1923-4287    

DOI:10.1139/cjr31-014

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

The action of hypochlorous acid on glycol-lignin in finely divided aqueous suspension, and in alkaline solution, is autocatalytic, the autocatalysis being due to formation of hydrochloric acid, which catalyzes the reaction strongly. Nitric acid apparently acts only by increasing the concentration of undissociated hydrochloric acid. The effect of the hydrochloric acid may be a direct catalytic effect of undissociated hydrochloric acid, or may be due to formation of chlorine.A comparison of the amounts of hypochlorous acid absorbed, and hydrochloric acid formed, by methylated and unmethylated lignin indicates that if ketomethylene groups are present in lignin they do not enolize sufficiently to play any appreciable part in the rapid reaction between hypochlorous acid and lignin.The rapid absorption of hypochlorous acid by lignin, dissolved in alkali, indicates that there is probably about 15% of a phenol nucleus in lignin. This value is supported by the rapid absorption of bromine from bromine water at very low concentrations, by lignin dissolved in alkali, and is based on the assumption of only one atom of halogen entering the phenol nucleus, which is true in the case of vanillin. If two or three halogen atoms enter the nucleus, this value of 15% has to be divided by two or three. It represents, in any case, a maximum value.The phenol nucleus accounts for only one third, or less, of the total rapid hypochlorous acid absorption. The remainder is probably due to addition of hypochlorous acid to an ethylene linkage, chlorination of a phenol ether, or a combination of both reactions.

ISSN:1923-4287    

DOI:10.1139/cjr31-015

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

The mechanism first proposed by Emil Fischer to explain the migration of acyl radicals in the case of glycerides of fatty acids receives strong confirmatory support in the isolation by the authors of a product analogous to the intermediate dioxolane derivative postulated by him. From the theoretical consideration it seemed highly probable that with any glycol monoester containing a carbonyl group of very pronounced negative polarity, the tendency to undergo cyclisation would be so pronounced as to permit of the isolation of the corresponding dioxolane ring.It is shown that all attempts to synthesize glycol monotrichloroacetate gave, instead, the ring isomer, namely, 2-hydroxy-2′-trichloromethyl-1,3-dioxolane. The latter is quite stable at temperatures below 90 °C., but at 100–110 °C. decomposes into ethylene carbonate, chloroform, and a certain amount of higher-boiling, unidentified products. In presence of a trace of pyridine the decomposition into chloroform and ethylene carbonate takes place smoothly and apparently quantitatively. Similarly, when ethylene oxide is treated with dichloroacetic acid, 2-hydroxy-2′-dichloromethyl-1,3-dioxolane is produced. On the other hand, acetic and monochloroacetic acids react to give the normal half-esters. Epichlorohydrin and glycidol on treatment with trichloroacetic acid give the corresponding ring compounds, namely 2-hydroxy-2′-trichloromethyl-4-chloromethyl-1,3-dioxolane and 2-hydroxy-2′-trichloromethyl-4-hydroxymethyl-1,3-dioxolane, respectively. The last-named compound thus represents the cyclic derivative postulated by Fischer as the intermediate product formed in acyl migration occurring in the case of glycerol derivatives. Trimethylene glycol treated with trichloroacetyl chloride gives 2-hydroxy-2′-trichloromethyl-metadioxane. They are all mobile, pleasant-smelling, transparent liquids which decompose when heated at ordinary pressure.The reaction of acetic, mono-, di-, and trichloroacetic acids on 1,2-anhydromannopyranose and 1,2-triacetyl mannopyranose is under investigation. Preliminary work appears to indicate the formation of the corresponding 1,3-dioxolane derivative of mannose in each case. The conclusion is drawn thatall organic monoesters of polyvalent alcohols, carbohydrates, polysaccharides, o-amino phenols, etc., containing a free hydroxyl group, the hydrogen atom of which is spatially in close proximity to the carbonyl group of the acyl radical, tend to pass over into a ring isomer. Theoretically, at least, there must exist in all of these cases an equilibrium between the open-chain and its corresponding cyclic isomer.Investigations of the structure of the monoacyl derivatives of glycerol, of carbohydrates, polysaccharides, amino phenols, etc., should permit of the isolation, in many cases, of the intermediate dioxolane or other ring concerned in the migration of the acyl radical. The existence is postulated of a definite equilibrium between the open-chain ester and the corresponding ring isomer in all monoesters of poly-alcohols in which spatial proximity of a hydroxyl to the carbonyl group exists, and the prediction is made of the probable isolation of many new cyclic isomers under investigation when appropriate consideration is given to their physical and chemical properties, such as stability, behavior towards acids, alkalies, etc.

ISSN:1923-4287    

DOI:10.1139/cjr31-016

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

In the presence of a small amount of sodium methylate, cyclohexanone and benzil form an addition product, which is a "semicyclic" 1:4-diketone. No derivatives of a bicyclic cyclo-heptane were found. Its most conspicuous chemical property is its sensitivity to mineral acids; among the reaction products is found a diphenyltetrahydrocumarone. Although the addition product exhibits the phenomenon of halochromism, the existence of a perchlorate is doubtful, and it did not form a free radical.

ISSN:1923-4287    

DOI:10.1139/cjr31-017

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

Degradation of calycanthine, by a method which has heretofore not been applied to alkaloids, namely, benzoylation with subsequent treatment with alkali, has yielded a well-defined crystalline substance, shown by analysis and synthesis to be benzoyl-N-methyltryptamine. The alternative, benzoyl-1-methyltryptamine, has also been synthesized for purpose of comparison. The bearing of the degradation product on the constitution of calycanthine is discussed. The partial structure developed for the alkaloid differs considerably from any that has been previously suggested for a natural product.

ISSN:1923-4287    

DOI:10.1139/cjr31-018

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

The work published in a previous communication has been extended and revised. Determinations of the density of carbon dioxide are shown for five temperatures from − 30° to + 77 °C., and over a pressure range of 760 to 250 mm. of mercury. The extrapolation of these curves to zero pressure shows a mean value for the atomic weight of carbon = 12.004 ± 0.003. A graph is included which shows the apparent molecular weight as a function of the temperature; molecular volumes have been calculated from this.The results give P.V.T. values for CO2in the above temperature and pressure range, with an accuracy considered to be greater than available data.

ISSN:1923-4287    

DOI:10.1139/cjr31-019

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

A method is presented whereby an accurate record of the daily hours of bright sunshine is made by an electric clock, controlled, through a relay, by the intensity of the light incident upon the cathode of a suitably exposed photo-electric cell.

ISSN:1923-4287    

DOI:10.1139/cjr31-020

出版商:NRC Research Press    

年代:1931

数据来源: NRC