摘要:

Indole-3-aldehyde, indole-3-carboxylic acid and its ethyl ester were reduced by excess lithium aluminum hydride to skatole. The expected reduction product, 3-hydroxymethylindole, was obtained by the action of sodium hydroxide on gramine methiodide. It and its alkyl ethers were readily reduced to skatole. 3-Hydroxymethylindole underwent self-condensation to 3,3′-di-indolylmethane in neutral and alkaline media, and with acidic reagents was converted to an oxygen-free polymeric substance. The mechanism of these reactions and of the hydrogenolysis is discussed

ISSN:0008-4042    

DOI:10.1139/v53-106

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The following deuterated 3-pentanones were synthesized, in some cases by modifications of the methods reported in the literature, and in others by deuterium exchange:

ISSN:0008-4042    

DOI:10.1139/v53-107

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Hemicelluloses, extracted from barley, flax, oat, rye, and wheat straw holo-celluloses, were composed predominantly of anhydro-D-xylose units, with small amounts ofL-arabinose andD-glucuronic acid. The hemicelluloses had degrees of polymerization ranging from 55 for oat to 185 for rye and were shown to be linear polysaccharides. Autoclaving in distilled water at 120 °C. yielded crystalline xylans from barley, rye, and wheat straw hemicelluloses. The basic structure of the hemicellulose was maintained in the crystalline xylans, which gave identical X-ray diffraction patterns and had similar, linear structures. The crystallization procedure was found to degrade the hemicellulose, removingD-xylose,L-arabinose, andD-glucuronic acid as components of hydrolytic fragments and leaving a pure xylan one sixth to one third the length of its parent hemicellulose. Depending on uronic acid content, the five hemicelluloses in water gave pH values ranging from 2–5 with consequent variations in resistance to hydrolysis during autoclaving

ISSN:0008-4042    

DOI:10.1139/v53-108

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Under identical conditions, corn starch amylose was more readily oxidized than the amylopectin by chromium trioxide dissolved in acetic acid – acetic anhydride, which was a nonswelling system. These differences in rate nearly vanished for samples dried through solvent exchange when the oxidant was dissolved in a swelling medium, 0.2 Maqueous sulphuric acid. The absolute rate of oxidation, however, was greatly reduced.Carboxyl groups in the oxystarches were satisfactorily estimated either by ion-exchange with calcium acetate or sodium bromide solutions, or by direct titration to about pH 8.5 with aqueous alkali. The samples retained chromium compounds which grossly interfered with the determination of total carbonyl groups by condensation with hydroxylamine hydrochloride; condensation with excess sodium cyanide, and estimation of the ammonia from the hydrolysis of the cyanohydrins, gave better results.Aldehyde groups in an oxystarch containing 0.16 M. of carboxyl and 0.14 M. of carbonyl groups were selectively oxidized with chlorous acid or alkaline hypoiodite, or were selectively condensed with sodium bisulphite solution. All three estimations indicated that about one-third of the carbonyl groups were aldehydes probably occupying the sixth positions in the glucose residues. The cyanohydrin of the oxystarch, when saponified and then hydrolyzed and reduced with boiling hydriodic acid, yielded the lactone of 2-methyl-4-hydroxyhexanoic acid, the recovery of which showed that at least 17% of the carbonyl groups occurred as 2-ketoglucose residues.

ISSN:0008-4042    

DOI:10.1139/v53-109

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Periodate oxidation of any one mono-O-methylglucopyranose and alkaline hydrolysis of the product yields a substance which can be positively distinguished by paper chromatography from the products formed under the same conditions from the other mono-O-methylglucopyranoses. Thus, the components of a mixture of the mono-O-methylglucopyranoses can be readily identified. The method appears useful for the identification of di-O-methylglucoses. Reduction with sodium borohydride prior to periodate oxidation renders the method useful for the identification of tri-O-methylglucoses. The potential value of the method, which can be used on a microscale, is illustrated by an application to the characterization of theO-methylglucoses derived from a water-solubleO-methyl-cellulose

ISSN:0008-4042    

DOI:10.1139/v53-110

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Ring closure at the 1,4-3,6-positions in monomethylenated mannitol and iditol imparts considerable lability to the cyclic methylene acetal group. The two derivatives, 1,4-3,6-dianhydro-2,5-methylene-D-mannitol and 1,4-3,6-dian-hydro-2,5-methylene-D-iditol, are easily cleaved at the 2,5-methylene positions by highly dilute acid and differ distinctly in this respect from 2,5-methylene-D-mannitol.

ISSN:0008-4042    

DOI:10.1139/v53-111

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Although there is a large body of literature dealing with the transition temperatures of the alkali metal salts of the fatty acids, it has not always been possible to feel confidence in their graphical determination. Hitherto few measurements have been made of the viscosity of soaps as a function of temperature and rate of shear, though such measurements promise to prove useful, as sharp changes have been observed in the regions of previously reported transition points. The viscosity apparatus is described and the results obtained with anhydrous sodium stearate given, from the aspect of transition temperatures and as a study of flow properties.

ISSN:0008-4042    

DOI:10.1139/v53-112

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The preparation of a series of dinitro-n-alkyl phenols is described. The dinitrophenols were characterized as their piperidine, morpholine, and cyclohexylamine salts. In the course of the work some new derivatives of thesen-alkyl phenols and intermediate hydroxyketones were obtained.

ISSN:0008-4042    

DOI:10.1139/v53-113

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

An apparatus for the microanalysis of gas mixtures is described with which volumes of gases as low as 5 cu. mm. at N.T.P. can be analyzed in the dry way. Two applications of the method are presented; the first is for carbon dioxide, the second is for the use of the diffusion of hydrogen through palladium in the presence of either carbon monoxide or methane for the analysis of hydrogen.

ISSN:0008-4042    

DOI:10.1139/v53-114

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

A kinetic study and analysis has been made of the effects of ionic strength, acid activity, temperature, and salt type on the dissolution of magnesium in acidic salt solutions. This is an example of the simplest type of corrosion involving hydrogen evolution. The results are interpreted in terms of the effects of the various factors on the structure of a surface film which must be magnesium oxide and/or hydroxide even in acidic solutions. The importance of internal dissolutions in the film at high concentrations of attacking reagent, for this and other cases, is shown. Owing to complex formation, under certain conditions an odd case of "chemical control" of the dissolution rate in this simplest case becomes evident. Corrosion potential measurements aid in the interpretation.

ISSN:0008-4042    

DOI:10.1139/v53-115

出版商:NRC Research Press    

年代:1953

数据来源: NRC