摘要:

The previously unknown 2,5,6-tri-O-methyl-D-glucose has been prepared fromD-glucose. Proof of the constitution of this new sugar derivative is based on its chemical reactions and method of synthesis.

ISSN:0008-4042    

DOI:10.1139/v56-112

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Phenyl isobutyrate has been found to undergo a normal Fries rearrangement with anhydrous aluminum chloride at 140 °C. to give a mixture of 2-hydroxy-(40%) and 4-hydroxy-isobutyrophenone (11%). When the reaction was carried out in nitrobenzene solution at room temperature the 4-isomer was formed in 86% yield. Methylation of these compounds furnished 2- and 4-methoxy-isobutyrophenone, identical with the compounds obtained by direct acylation of anisole. Reduction of the hydroxy-isobutyrophenones, which were also prepared by direct acylation of phenol, afforded an alternative route to the isobutylphenols. The orientation of each methoxy ketone was verified by oxidation to the corresponding acid.

ISSN:0008-4042    

DOI:10.1139/v56-113

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

CrystallineD-mannitol penta- and hexa-nitrates, methyl-β-D-glucopyranoside tetranitrate, and maltose and cellobiose octanitrates were prepared as model substances of known constitution for study of denitration reactions possibly applicable to polysaccharide nitrates. Heterogeneous catalytic hydrogenation smoothly regenerated the parent carbohydrates from the model compounds in nearly quantitative yield and removed 0.42 and 0.63 nitrate groups per glucose unit from cellulose nitrates of 13.3 and 10.7% N respectively. Raney nickel was conveniently removed from the hydrogenated cellulose nitrates by means of a magnet. The action of methyl magnesium iodide, lithium aluminum hydride, or low-pressure hydrogenation with a homogeneous cupric acetate catalyst caused less complete denitration of the mannitol or cellobiose polynitrates. The nitration–fractionation–denitration sequence as a means of isolation of undegraded polysaccharides from natural sources is discussed.

ISSN:0008-4042    

DOI:10.1139/v56-114

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

A semiempirical equation is presented relating the activation energies of some fifty solvolyses of benzenesulphonic esters to physical properties of the solvolyzing medium. The equation predicts more than 70% of these activation energies to better than 300 cal./gm-mol. The significance of the equation is discussed on the basis of a continuous spectrum of mechanisms intermediate between the accepted SN1 and SN2 types. A suggested interpretation of the logPZ(activation entropy) term is also offered.

ISSN:0008-4042    

DOI:10.1139/v56-115

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

It has been shown that the carbon–oxygen bond of nitrate esters is susceptible to cleavage by certain representative nucleophilic reagents, of which sodium iodide, sodium cyanide, and potassium thiocyanate have received particular attention. Allyl, 3-hydroxypropyl, 4-fluorobutyl, hexyl, and benzyl nitrate were examined in order to determine the effect if any of functional groups on the ease and efficiency of cleavage.

ISSN:0008-4042    

DOI:10.1139/v56-116

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The main organic product of the reaction was hydrogen cyanide, the maximum yield of which was practically independent of temperature in the range 130 ° to 330 °C, and appeared to correspond to about one-half the active nitrogen concentration present. Presumably the reactant or products, or both, caused deactivation of about one-half the active nitrogen. Small amounts of butane, propane, ethane, methane, propylene, ethylene, acetylene, and cyanogen were also found in the products.

ISSN:0008-4042    

DOI:10.1139/v56-117

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The ultraviolet absorption spectra of 1,2-benzanthracene, all twelve mono-methyl derivatives, and six dimethyl derivatives have been measured (a) at room temperature inn-heptane solution, (b) at −100 °C. inn-pentane solution. An analysis of the band envelopes indicates that most of the absorption between 33,000 and 25,000 cm.−1arises from two series of overlapping bands. The members of each series are spaced at intervals of approximately 1400 cm.−1. The spacing between the two band series and their relative intensities are dependent on the nature and position of the alkyl substituents. Absorption between 40,000 and 33,000 cm.−1can be treated in a similar manner. Other fine structure is also observed. It is considered most probable that each of the overlapping series of bands is associated with a separate electronic excitation. The significance of these observations is considered in relation to the theoretical treatments of the energy levels of 1,2-benzanthracene as developed by Klevens and Platt and by Moffitt.

ISSN:0008-4042    

DOI:10.1139/v56-118

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Crystalline ethyl and propyl 1,2-orthoacetates of α-D-glucopyranose triacetate were prepared. Conclusions are drawn regarding the chemical properties and configurations of these compounds which are based on the conformation of the 1,2-cyclic carboxonium ion believed to be formed when the substances are treated with acetic acid.

ISSN:0008-4042    

DOI:10.1139/v56-119

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

A convenient synthesis ofDL-hydroxy-ornithine is described. Starting from diethyl allylmalonate, it involves treatment with sulphuryl chloride followed by hydrolysis and distillation to give a 90% yield of 2,5-dichloro-4-valerolactone. Condensation of this with two equivalents of potassium phthalimide in dimethyl-formamide gives a quantitative yield of crude 2,5-diphthalimido-4-valerolactone. This lactone is converted quantitatively by acid hydrolysis toDL-γ-hydroxyornithine, isolated as the dihydrochloride of the corresponding 2,5-diamino-4-valerolactone. The over-all yield calculated from allyl chloride is 80%.

ISSN:0008-4042    

DOI:10.1139/v56-120

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The potentiometric method for the determination of aluminum proposed by Treadwell and Bernasconi has been modified for use on a semimicro scale and applied successfully to the analysis of pulp and paper ash. Samples containing as little as one milligram of aluminum have been titrated with an accuracy of 0.003 milligrams or better.

ISSN:0008-4042    

DOI:10.1139/v56-121

出版商:NRC Research Press    

年代:1956

数据来源: NRC