摘要:

The synthesis of glucose-1-methylphosphonate and isopropyl glucose-1-methylphosphonate has been attempted. Although the intermediates were successfully prepared, deacetylation failed to give the desired products.

ISSN:0008-4042    

DOI:10.1139/v57-083

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The rate of growth of butadiene popcorn polymer seed in the presence of methyl methacrylate monomer vapor was found to be logarithmic with time and very sensitive to the presence of hydroquinone in the monomer. The resulting butadiene – methyl methacrylate graft polymer was homogeneous in appearance. No satisfactory kinetic mechanism can be presented at this time.

ISSN:0008-4042    

DOI:10.1139/v57-084

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The addition of ethyl radicals to ethylene has been studied in the temperature range 58° to 123 °C. The radicals were produced by the mercury photosensitized decomposition of hydrogen in the presence of ethylene, and the rate of the addition reaction was measured in terms of the rate of formation ofn-hexane by the combination of ethyl and butyl radicals. Corrections were made for the non-uniformity of radical concentrations in the reaction zone. Assuming a negligible activation energy for the combination of two ethyl radicals, the activation energy for the addition reaction is 5.5 kcal. per mole; the steric factor, relative to the square root of the steric factor for ethyl radical combination, is 5.0 × 10−5.

ISSN:0008-4042    

DOI:10.1139/v57-085

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

A novel method for the preparation of 4-O-methyl-D-glucuronic acid is described. This sugar and 4-O-methyl-D-glucose were obtained in good yield by two different series of reactions from 2-O-(4-O-methyl-D-glucopyranuronosido)-D-xylose, an acid hydrolysis product of the hemicellulose ofPopulustacamahaccaMill.

ISSN:0008-4042    

DOI:10.1139/v57-086

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The Williamson ether synthesis has been applied to the preparation of polyoxyethyleneglycol mono- and di-ethers. These were obtained by reacting the mixed potassium salts of hexaoxyethyleneglycol with alkyl or aryl halides. Hexaoxyethyleneglycol monoethers of the type R•O(CH2CH2•O)6H, (R = n-C10H21,n-C12H25,n-C14H29, andp-iso-C8•H17•C6H4•O•CH2CH2) and diethers of the type R•O(CH2•CH2•O)6•R, (R = n-C10H21,n-C12H25, andn-C14H29) have been prepared in pure state and some of their properties determined.

ISSN:0008-4042    

DOI:10.1139/v57-087

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Mercury photosensitized decomposition oftrans-2,3-epoxybutane has been studied at 25°. The quenching efficiency of this compound is 1.23 relative to the quenching efficiency of N2O taken as unity; the quenching cross section is, therefore, 19 Å2(taking 3.6 Å2for the quenching cross section ofn-butane). The main products formed are isobutanal, C2H6, CO, C2H4, C3H8, CH3CHO, C2H5CHO, CH3COC2H5, CH4, and H2. The yields of most of the products decrease with increasing pressure while those of C2H6, CH4, and H2remain essentially pressure independent. Possible reaction mechanisms are discussed.

ISSN:0008-4042    

DOI:10.1139/v57-088

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Data are presented showing temperature dependence of the rate of hydrolysis of methyl, ethyl, isopropyl, andn-propyl benzenesulphonates in water. The heat of activation is shown to be temperature dependent to the extent of −30 to −40 cal./mole deg. Since, in solvolysis, the properties of water favor ionization over nucleophilic displacement, it is suggested that these temperature coefficients, ΔCp‡, and the accompanying entropy differences, ΔS‡, can be rationalized in terms of variations in the reorganization of the solvent about the transition state.

ISSN:0008-4042    

DOI:10.1139/v57-089

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

A conductometric method is described for the determination of rates of solvolyses in nonaqueous media with an accuracy of better than ± 0.5% ink. The heat of activation derived from the results so obtained is shown to have a temperature coefficient (ΔCp‡) of −21 cal./mole deg.

ISSN:0008-4042    

DOI:10.1139/v57-090

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

From dielectric constant measurements in benzene for the two halides mercuric chloride and mercuric bromide, the dipole moments are 1.23 and 0.95 D. respectively. Thus, they apparently possess angular structures.

ISSN:0008-4042    

DOI:10.1139/v57-091

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Extractive-free aspen wood (Populustremuloides) was extracted with water, followed by alkaline solutions of successively increasing concentration, and finally with alkaline borate solution. Hemicellulose fractions (I–IX) were thus obtained, and some of these were further subdivided into components which formed water-insoluble copper complexes (A) and those which did not (B). Analytical data are recorded for each fraction.One of the fractions (V) represented 19% by weight of the original wood. Hydrolysis of the methylated material gave 2,3,5-tri-O-methyl-L-arabinose, 2,3,4-tri-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2- and 3-mono-O-methyl-D-xyloses, and three acidic fragments as the major components.When V was treated with an enzyme preparation, 80% by weight of the material was hydrolyzed to simple sugars, and an enzyme-resistant polysaccharide fraction remained. Methylation of the latter, followed by hydrolysis, afforded, in addition to those methylated sugars described above, 2,3,4,6-tetra-O-methyl-D-mannose.A mannose-rich hemicellulose fraction (VIIIA) was also methylated and then hydrolyzed. The major products were 2,3,4,6-tetra-O-methyl-D-mannose, 2,3,6-tri-O-methyl-D-mannose, and 2,3,6-tri-O-methyl-D-glucose. The significance of these results is discussed.

ISSN:0008-4042    

DOI:10.1139/v57-092

出版商:NRC Research Press    

年代:1957

数据来源: NRC