摘要:

Partial acid hydrolysis of an arabinogalactan from tamarack wood yielded:(I)L-arabinose,(II)D-galactose,(III) 3-O-β-L-arabinopyranosyl-L-arabinose,(IV) 6-O-β-D-galactopyranosyl-D-galactose,(V) 3-O-β-D-galactopyranosyl-D-galactose,(VI)O-D-galactopyranosyl(1 → 6)-O-D-galactopyranosyl(1 → 6)-D-galactose,(VII) 3,6-di-O-(galactopyranosyl)-D-galactopyranose,(VIII)O-D-galactopyranosyl(1 → 3)-O-D-galactopyranosyl(1 → 3)-D-galactose,(IX)O-D-galactopyranosyl(1 → 6)-O-D-galactopyranosyl(1 → 3)-D-galactose,(X)O-D-galactopyranosyl(1 → 6)-O-D-galactopyranosyl(1 → 6)-O-D-galactopyranosyl(1 → 3)-D-galactose,(XI)O-D-galactopyranosyl(1 → 6)-O-D-galactopyranosyl(1 → 3)-O-D-galactopyranosyl(1 → 3)-D-galactose.A previously published structure for the tamarack polysaccharide was revised to show that not more than two consecutive 1 → 3 or 1 → 6 linkages respectively were present in the main core of the repeating unit. Some of the 6-O-β-D-galactopyranosyl-D-galactose units occurred as side chains as well as in the main body of the molecule.

ISSN:0008-4042    

DOI:10.1139/v61-199

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

Crystals of 1,4-dibromonaphthalene are monoclinic with eight molecules in a unit cell of dimensionsa = 27.45,b = 16.62,c = 4.09 Å; β = 91.9°; space groupP21/aThe high proportion of bromine in the crystal probably precludes location of the carbon atoms with sufficient precision to give accurate molecular dimensions, and it has therefore not been considered worth while proceeding beyond the detailed examination of the projection along the shortc-axis. There are two molecules in the asymmetric unit, and the solution of the structure fromhk0 Patterson and Fourier projections has indicated that these two molecules are related, at least in projection, by a pseudo center of symmetry. The projected bond distances indicate significant deviations of the bromine atoms from the aromatic plane. Approximate values of the bond lengths in the molecule have been deduced from the projected distances and estimated orientation angles.

ISSN:0008-4042    

DOI:10.1139/v61-200

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

Delcosine has been assigned tentatively the same C—N skeleton as lycoctonine. In lycoctonine, ring A carries at C-1 a methoxyl group which is directed away from the nitrogen ring. In delcosine, C-1 carries a hydroxyl group which has the opposite configuration and is directed towards the nitrogen. An attempt to correlate the two structures first involves epimerization at C-1 in delcosine. This has been carried out by oxidation of desethyldelcosine to an azomethine, the ethiodide of which, by the action of methanolic potassium hydroxide, is converted to oxo-1-epidelcosine in two steps. Oxo-1-epidelcosine in an acid-catalyzed rearrangement is transformed to a pinacone which, after methylation, gives O,O-dimethyl-anhydro-oxo-1-epidelcosine. This compound was compared with O-methylanhydro-oxolycoctonine, prepared from oxolycoctonine, but was not identical. Removal of a methoxyl, which in each compound is ortho to a carbonyl, by the action of sodium amalgam, produced O,O-dimethyl-6-desmethoxy-anhydro-oxo-1-epidelcosine and O-methyl-6-desmethoxy-anhydro-oxolycoctonine, which are not identical, but show in their infrared spectra much less dissimilarity than the spectra of the pair of compounds from which they were derived. These results are discussed in terms of the structure of delcosine.

ISSN:0008-4042    

DOI:10.1139/v61-201

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The kinetics of reaction between 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a wide variety of phenols have been studied. The rate of disappearance of DPPH is of first order with respect to both the DPPH and the reacting phenol. The rates of reaction can be roughly correlated with the Hammett σ value of the phenol substituent in the range −0.4 < σ < 0.2, a ρ value of −6 being obtained.t-Butyl groups in both ortho positions of the phenol give rise to steric hindrance, the reduction in rate being largely due to a reduction in theAfactor. Hydrogen abstraction from the less reactive phenols is strongly retarded by the product, 2,2-diphenyl-1-picrylhydrazine.The rate-determining step probably involves the abstraction of a hydrogen atom from the phenol by the DPPH to give diphenylpicrylhydrazine and a phenoxy radical. The retardation by diphenylpicrylhydrazine is readily explained if this primary step is reversible.

ISSN:0008-4042    

DOI:10.1139/v61-202

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

5-O-Methyl-L-arabinose has been synthesized by an unambiguous route in whichO-benzyl groups were used to block positions 2 and 3 in theL-arabinose molecule. In addition to the usual indirect proofs of structure, a direct proof is described involving isolation of the product from periodate oxidation of the 5-O-methyl-L-arabinose. Two new derivatives, the phenylhydrazide and amide of 5-O-methyl-L-arabonic acid, were prepared.

ISSN:0008-4042    

DOI:10.1139/v61-203

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The reaction has been studied in a fast-flow system by introducing nitric oxide in the gas stream with excess active nitrogen. The nitrogen atom consumption was determined by titrating active nitrogen with nitric oxide at different positions along the reaction tube. The rate constant is found to bek1 = 1.83(± 0.2) × 1015 cc2mole−2sec−1at pressures of 3, 3.5, and 4 mm, and with an unheated reaction tube.The homogeneous and surface decay of nitrogen atoms involved in the above system were studied using the nitric oxide titration method, and the rate constants were found to bek3 = 1.04 ± 0.17 × 1016 cc2mole−2sec−1, andk4 = 2.5 ± 0.2 sec−1(γ = 7.5 ± 0.6 × 10–5), respectively, over the range of pressures from 0.5 to 4 mm with an unheated reaction tube.

ISSN:0008-4042    

DOI:10.1139/v61-204

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The toxin produced byHelminthosporiumsativumP.K. and B•4has been isolated in crystalline form. It has the formula C15H22O2and has been shown to contain one saturated aldehyde function, one α,β-unsaturated aldehyde, and two carbocyclic rings.

ISSN:0008-4042    

DOI:10.1139/v61-205

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

In hydrocarbon or ether solvents, the sodium or potassium salt of fluorene or of 9-benzoylfluorene reacts with an equimolar amount of benzoyl chloride to form 9,1′-benzoyloxybenzylidenefluorene (I). The reaction of equimolar quantities of the lithium salt of fluorene or of 9-benzoylfluorene and benzoyl chloride in ether solvents gives rise to a mixture of 9,9-dibenzoylfluorene (II) and 9,1′-benzoyloxybenzylidenefluorene (I), but in hydrocarbon solvents produces only 9,9-dibenzoylfluorene (II).Only 9-benzoylfluorene is isolated from the reactions of the monometal salts of fluorene or of 9-benzoylfluorene with ethyl benzoate.

ISSN:0008-4042    

DOI:10.1139/v61-206

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The viscosities of some alkoxides of titanium, zirconium, cerium (IV), thorium, and tin (IV) have been measured in the temperature range 25–40 °C. The liquid structure in these compounds is discussed in terms of the activation energy, free energy, and entropy of activation for viscous flow, and the energies of cohesion and vaporization.

ISSN:0008-4042    

DOI:10.1139/v61-207

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

Infrared spectra of benzoic,o-chlorobenzoic, and salicylic acids in the range 700 to 3800 cm−1have been studied. Measurements have been made on the three acids in carbon tetrachloride and benzene solutions, at a number of concentrations in each case. The results are interpreted in terms of the molecular species present in each solution and the effect of the solvents on these species. Assignments have been made of the observed bands to the various vibrational modes characteristic of the COOH group.

ISSN:0008-4042    

DOI:10.1139/v61-208

出版商:NRC Research Press    

年代:1961

数据来源: NRC