bluuebunny/crossref_metadata_2025 huggingface dataset:
THE ACIDITY OF NITROGUANIDINE AND ITS HOMOLOGUES
Authors: Amos A. A. , Cooper P. D. , Nishizawa E. , Wright George F
Published: May 2006

It has been shown that nitroguanidine, nitriminoimidazolidine, and 1-benzyl-2-nitriminoimidazolidine behave like urea by formation of potassium salts which completely hydrolyze in water. By contrast to true primary nitramines with which they might be considered to be tautomeric, the nitrimines are classed like urea as practically neutral compounds. Despite this ostensible tautomerism which was formerly evoked to explain the survival of nitroguanidine and nitriminoimidazolidine in alkaline solution it is now believed that the salts of nitroguanidine and nitraminoimidazolidine, from which the original nitrimines are regenerated upon acidification, are not intermediates, but rather end products, in the slow reaction with alkali. The intermediate is now postulated as an hydroxyisonitraminate anion from which the several products of the reaction are formed by appropriate fission. Presumably this anionic intermediate also is operative when tetraethylnitroguanidine or 1,3-dibenzyl-2-nitriminoimidazolidine is converted by alkali into tetraethylurea and 1,3-dibenzyl-2-inuclazolidine respectively.
STEROIDS AND RELATED PRODUCTS: XVI. AN IMPROVED SYNTHESIS OF 11-DEHYDRO-17α-METHYLPROGESTERONE
Authors: Engel Ch. R. , Just G. , Buttery R.
Published: May 2006

An improved synthesis of 11-dehydro-17α-methylprogesterone, previously synthesized by this group, has been devised. The new hormone analogue has the same luteoid activity as 17α-methylprogesterone; in this case, the 11,12-unsaturation has no potentiating effect on the progestational activity. Some stereochemical aspects of the Faworsky rearrangement of 17α-halo-20-keto steroids are discussed in a preliminary fashion.
THE REVERSIBILITY OF AROMATIC MERCURATION
Authors: Malaiyandi M. , Sawatzky H. , Wright G. F
Published: May 2006

The ratio of isomeric bisperchloratomercuribenzenes obtained from the monomercurial and mercuric perchlorate in perchloric acid varies slightly with concentration of the acid, but is preponderantly meta. However, more para than meta isomer is obtained under conditions where the para isomer is insoluble in the system. This indicates a mobile equilibrium among the isomers, which is found to extend to all of the polymercuration products. The postulated intermediate for the equilibration, which is 1,2,4-trichloratomercuribenzene, is indicated by the isolation of the similarly oriented 1,2,4,5-perchloratomercuritetrakisbenzene. Although none of the ortho-diperchloratomercuribenzene can be found from this reaction in perchloric acid, it is the principal isomer when phenylmercuric acetate is acetoxymercurated neat.
MOLECULAR ADDITION COMPOUNDS OF TRIOXAN
Authors: Hamer Douglas , Leslie James
Published: May 2006

not available
FREE RADICALS BY MASS SPECTROMETRY: XXVI. PRIMARY STEPS IN THE MERCURY-PHOTOSENSITIZED DECOMPOSITION OF METHYL ACETATE
Authors: Pottie R. F. , Lossing F. P.
Published: May 2006

The Hg(3P1)-photosensitized reaction of methyl acetate at micron pressures in the presence of 8 mm of helium has been examined in a flow system by mass spectrometry. At 55 °C the primary dissociation is mainly into acetyl and methoxy radicals. An alternative dissociation into CO2 and two CH3 radicals occurs with a frequency of about one fifth of the principal reaction. A small amount of COOCH3 radical is also formed. No CH3CO2 radicals could be found. Since the yield of H2 is less than 2% of the methyl acetate decomposed, a primary dissociation to give H atoms and CH3COOCH2 or CH2COOCH3 radicals is quite small.
FURTHER EVIDENCE FOR CYCLIC MONOMERS IN HEATED LINSEED OIL
Authors: McInnes A. G. , Cooper F. P. , MacDonald J. A.
Published: May 2006

The distillable esters of heated linseed oil contain a fraction, designated NAFD, which fails to form an adduct with urea. NAFD itself has now been separated into three fractions by gas-liquid partition chromatography. The chemical structure of these component esters was investigated by means of their infrared spectra and by analysis of the products obtained on oxidation of the esters with periodate–permanganate. It is concluded that all the components have the same carbon skeleton, namely, 1-propyl-2-alkenecarboxycyclohexene, but differ in the position of the double bond in the side chain.
THE DIFFERENTIAL THERMAL ANALYSIS OF WOOD
Authors: Arseneau D. F.
Published: May 2006

Differential thermal analysis was used to study the thermal breakdown of balsam fir and its components in air from 50° to 420 °C. In this range, the thermogram of balsam fir is simply a composite of the individual thermograms of the components of the wood, with little, if any, interaction between the components.
HYDROGEN EXCHANGE BETWEEN CELLULOSE AND WATER: I. MEASUREMENT OF ACCESSIBILITY
Authors: Sepall O. , Mason S. G.
Published: May 2006

Estimates of the extent of the hydrogen exchange reaction between cellulose and water vapor determined by an improved method using tritiated water and by the use of heavy water were usually in good agreement. With certain samples, surface roughness had a small effect upon the measurement of tritium radioactivity in cellulose.The accessibility or limiting extent of the exchange increased slightly with relative humidity in the range 20 to 100% and was attributed to the reduction of crystalline order reported recently in similar experiments.In contrast to cellulose whose accessibility corresponds approximately to the amorphous fraction, a partially crystalline amylose was 100% accessible while an amorphous xylan was 52% accessible, indicating that in these substances the accessibility and the fraction of amorphous material are not identical.
HYDROGEN EXCHANGE BETWEEN CELLULOSE AND WATER: II. INTERCONVERSION OF ACCESSIBLE AND INACCESSIBLE REGIONS
Authors: Sepall O. , Mason S. G.
Published: May 2006

Exchange of hydrogen between water and some of the inaccessible hydroxyl groups in cellulose resulted from changes in the relative humidity and was most pronounced near 0 and 100% RH. A similar exchange occurred during prolonged immersion in liquid water. The extent of the reaction varied in different samples, increased with temperature, and was reproducible. By repeatedly wetting and drying cellophane, the exchange was cumulative and all the hydroxyl groups became exchanged after up to 100 cycles. The accessibility decreased slightly after repeated drying. The measurements were made by exchange with deuterated and tritiated water.The behavior was interpreted as an interchange of ordered and disordered regions resulting from molecular rearrangement caused by interaction between cellulose and water.
OZONOLYSIS OF UNSATURATED FATTY ACIDS: I. OZONOLYSIS OF OLEIC ACID
Authors: Ackman R. G. , Retson M. E. , Gallay L. R. , Vandenheuvel F. A.
Published: May 2006

Ozonolysis of oleic acid in methanol, a reacting solvent, with subsequent decomposition of the ozonide products by hydrogen peroxide in formic acid, gives yields of principal dicarboxylic acid fission products exceeding 95% with a minimum of secondary acidic products. The method is highly reproducible and offers unique advantages in the total recovery of the dicarboxylic acids and the elimination of peroxidic materials. The principal non-acidic by-products were tentatively identified as the Csalcohols and their formyl esters.
OCTAHALOGENODIBENZO-p-DIOXINS
Authors: Kulka Marshall
Published: May 2006

Pentahalogenophenols have been converted to 1,2,3,4,6,7,8,9-octahalogenodibenzo-p-dioxins in almost quantitative yields using the halogens or halogen-producing compounds as initiators of the reaction. It is suggested that an intermediate in this reaction is the pentahalogenophenoxy radical.
α-KETOETHERS: II. INFRARED SPECTRA AND ROTATIONAL ISOMERISM OF PHENACYL ETHERS
Authors: Yates Peter , Lipinsky Sherry , Vossius Dorothea
Published: May 2006

Bifurcation of the carbonyl-stretching bands in the infrared spectra of several phenacyl ethers has been observed and is interpreted in terms of rotational isomerism.
THE IRRADIATION OF β-IONONE
Authors: Mayo P. de , Stothers J. B. , Yip R. W.
Published: May 2006

not available
THE VIBRATIONAL SPECTRA OF SULPHURYL AND THIONYL HALIDES
Authors: Gillespie R. J. , Robinson E. A.
Published: May 2006

New assignments are proposed for the fundamental frequencies of SOF2, SOCl2, SO2Cl2, SO2F2, and SO2FBr, based on new measurements of the Raman spectrum of SO2Cl2 and previous measurements of the infrared and Raman spectra of these molecules. The fundamental frequencies of these molecules are found to be related to each other and to those of similar molecules when the normal modes are described in terms of characteristic vibrations of the SO, SO2, S(Hal), and S(Hal)2 groups.
POLAROGRAPHIC DETERMINATION OF THE DISSOCIATION CONSTANT OF THE SULPHYDRYL GROUP AND DIFFUSION COEFFICIENT MEASUREMENTS OF THIOMALIC ACID
Authors: Kapoor R. C. , Agrawal O. P. , Seth T. D.
Published: May 2006

Polarographic study of thiomalic acid has been made in the pH range 1–12.5 using Britton–Robinson buffer at 30°. The half-wave potential [Formula: see text] values have been used to determine the pK3 (SH) value of the acid (pK3 = 10.55).The diffusion current obtained in these experiments has been utilized to calculate the diffusion coefficients of the different charged species of thiomalic acid. The values thus obtained for the respective species are H3A = 1.20 × 10−5 cm2/sec; H2A− = 1.16 × 10−5 cm2/sec; HA−− = 1.08 × 10−5 cm2/sec; and A−−− = 7.67 × 10−6 cm2/sec.The standard potential of the reaction[Formula: see text]has been calculated as +0.266 volt vs. N.H.E.
PRIMARY QUANTUM YIELD DETERMINATION BY INTERMITTENT ILLUMINATION IN THE REACTION OF METHANOL VAPOR WITH Hg 6(3P1) ATOMS
Authors: Knight Arthur R. , Gunning Harry E.
Published: May 2006

The decomposition of methanol vapor by Hg 6(3P1) atoms has been studied under intermittent illumination conditions, in a static system at 25 °C. The behavior of the NO-inhibited reaction under intermittent illumination has also been examined.For the pure substrate at a pressure of 50 mm, the quantum yield of hydrogen formation, Φ(H2), was found to rise steadily toward unity with decreasing light period (tL). The maximum value of Φ(H2) at a given tD could only be obtained if the dark period (tD) exceeded 100 mseconds. At the shortest tL studied, 0.156 msecond, Φ(H2) was 0.89 compared with the steady illumination value, at zero extent of reaction, of 0.46. A linear relation was found to obtain between Φ(H2) and log (tL) at a given tD Extrapolation showed that Φ(H2) would be unity at tL = 0.040 msecond.For a mixture of 4.8 mm of NO and 50 m of CH3OH, Φ(CH3ONO) was found to rise from its steady illumination value of 0.14 to 0.27 at a sector speed of 300 r.p.m., with a dark/light ratio of 20. At higher speeds the quantum yield decreased again.From the study it is concluded that the primary process of H atom detachment is at least 89% efficient, and that the primary quantum yield is likely unity. The fact that the quantum yield under steady illumination is only 0.46 is attributed to the consumption of H atoms by radical addition processes of which the most probable is the addition of H to CH2OH. For the inhibited reaction the low value of Φ(CH3ONO) under steady illumination is ascribed to the abstractive attack of CH3O on NOH.The kinetic effects of intermittent illumination are discussed, in the light of the results. It is concluded that the technique should be of considerable value in primary process studies in mercury photosensitization.
EXTRACELLULAR ACIDIC POLYSACCHARIDES FROM C. INSIDIOSUM AND OTHER CORYNEBACTERIUM SPP.
Authors: Gorin P. A. J. , Spencer J. F. T.
Published: May 2006

The extracellular polysaccharide of Corynebacteriuminsidiosum, the causative agent of alfalfa wilt, contains D-glucose, D-galactose, and L-fucose in the proportions 2:3:4, with smaller amounts of an unknown acid. Partial acid hydrolysis of the polysaccharide gives 4-O-β-D-glucopyranosyl-L-fucose and 4-O-β-D-glucopyranosyl-(3-O-D-galactopyranosyl)-L-fucose as neutral oligosaccharides. Also formed are D-galactose, substituted in the 4-position with an unknown acid, and 4-O-β-D-glucopyranosyl-(3-O-D-galactopyranosyl)-L-fucose, which has the 4-position of the galactopyranosyl moiety substituted in a similar way. It appears that the above oligosaccharides represent the structure of the polysaccharide to a considerable extent.
COMPLEX PERIODATES AND TELLURATES
Authors: Lister M. W.
Published: May 2006

not available
CO-ORDINATION COMPLEXES OF TITANIUM (IV) HALIDES: II. PREPARATION AND INFRARED SPECTRA OF THE COMPLEXES OF TITANIUM TETRACHLORIDE WITH DIESTERS OF α,ω-DICARBOXYLIC ACIDS AND COMPARISON WITH ANALOGOUS COMPLEXES OF ZIRCONIUM TETRACHLORIDE AND TIN TETRACHLORIDE
Authors: Rivet Ernest , Aubin Real , Rivest Roland
Published: May 2006

Co-ordination complexes between diesters of α,ω-dicarboxylic acids and titanium tetrachloride, tin tetrachloride, and zirconium tetrachloride have been prepared. The analytical results, the infrared spectra, the melting points, and the molecular-weight determinations indicate that for the titanium and zirconium complexes, two types of complexes are obtained, one having a general formula MX4•1 diester in which chelate rings from five to nine atoms are formed and the other one, 2MX4•1 diester in which there are two 4-membered rings per complex molecule. With tin tetrachloride only one type of complex is formed, which has two tin tetrachlorides and two diesters per complex molecule.
π-BONDING IN INORGANIC COMPOUNDS: IV. ROLE OF UNPAIRED ELECTRONS IN HEXAHALO COMPLEXES
Authors: Westland A. D. , Bhiwandker N. C.
Published: May 2006

A study of dπ–pπ bonding in paramagnetic compounds having the potassium chloroplatinate structure is described. It is shown that the magnetic superexchange effect is approximately proportional to the number of unpaired electrons in t2g5 and t2g4 systems but there is an irregularity in the t2g3 system of potassium chlororhenate. This singularity of the t2g3 case is considered to be a result of the orbital and crystal symmetries. The magnetic properties of the compounds are related to the extent of π-bonding stabilization in octahedral complexes having various configurations t2gn on their central atoms.
SUBSTITUTION AT OCTAHEDRAL CENTERS: II. EFFECT OF SALTS UPON THE RATE OF HYDROLYSIS OF THE HALOPENTAMMINECHROMIUM(III) IONS
Authors: Jones T. P. , Harris W. E. , Wallace W. J.
Published: May 2006

A study of the hydrolysis of the halopentamminechromium(III) ions in the presence of the sodium salts of weak acids reveals a rate acceleration due to specific ion-pair formation. The acceleration is due partly to a charge-transfer effect and partly to the fact that the ion helps to maintain the octahedral configuration of the complex in the transition state. It is concluded that the reaction occurs by dissociation, but without collapse of the structure to a five-co-ordinated intermediate.
CONSTITUTION OF A GLUCOMANNAN FROM THE SAPWOOD OF SUGAR MAPLE (ACER SACCHARUM)
Authors: Adams G. A.
Published: May 2006

A glucomannan containing D-mannose and D-glucose in a molar ratio of 7:3 has been isolated from sugar maple sapwood. Electrophorectic examination in acetate and borate buffers showed that the polysaccharide was essentially homogeneous. Methylation and hydrolysis of the glucomannan yielded the following O-methyl ethers:2,3,4,6-tetra-O-methyl-D-glucose (1.1%),2,3,4,6-tetra-O-methyl-D-mannose (2.3%),2,3,6-tri-O-methyl-D-glucose (23.4%),2,3,6-tri-O-methyl-D-mannose (65.9%),2,3-di-O-methyl-D-glucose (2.6%),2,3-di-O-methyl-D-mannose (2.7%).These data in conjunction with periodate oxidation results and estimates of the degree of polymerization indicated that the glucomannan was composed of 25–27 hexose units linked β(1 → 4) in a linear structure. The chains were terminated predominately by D-mannose units; traces of D-xylose were present in terminal positions only and appeared to be part of the glucomannan molecule.
CONFIGURATION OF GLYCOSIDIC LINKAGES IN OLIGOSACCHARIDES: IX. SYNTHESIS OF α- AND β-D-MANNOPYRANOSYL DISACCHARIDES
Authors: Gorin P. A. J. , Perlin A. S.
Published: May 2006

The Königs–Knorr condensation of 4,6-di-O-acetyl-2,3-O-carbonyl-α-D-mannopyranosyl bromide with 1,2,3,4-tetra-O-acetyl-β-D-glucose provides a synthetic route to 6-O-β-D-mannopyranosyl-D-glucose. When some other derivatives of α-D-mannopyranosyl bromide—the 2,3,4,6-tetra-O-benzoyl-, 3,4,6-tri-O-acetyl-, or 3,4,6-tri-O-acetyl-2-O-benzyl derivative—are used as the halide component the α-D-linked isomer of this disaccharide is produced. The steric outcome of Königs–Knorr syntheses involving these and other derivatives of α-D-mannopyranosyl bromide is discussed in terms of the influence of neighboring groups, and of conformational and solvent effects.Lead tetraacetate oxidation of 6-O-β-D-mannopyranosyl-D-glucose, followed by reduction, affords 4-O-β-D-mannopyranosyl-D-erythritol, a metabolite produced by Ustilago species (PRL 627).
REVERSIBLE N,O-HALOACYL SHIFT IN SERINE DERIVATIVES WITH ANTITUMOR ACTIVITY
Authors: Levi I. , Weed J. W. R. , Laflamme G. , Koller A. E.
Published: May 2006

Large doses of N-dichloroacetyl-DL-serine sodium salt were required to cause regression of Sarcoma-37 in mice. About 56% of the unchanged compound was recovered from the urine. These observations suggest that the antitumor activity may reside in a metabolic product of the N-dichloroacetyl serine. It is postulated that the active compound is the corresponding O-dichloroacetyl-DL-serine formed from the N-acyl compound by an in vivo enzymatically controlled shift which takes place via the hydroxyoxazolidine and (or) the oxazoline rings. O-Dichloroacetyl-DL-serine hydrochloride was prepared by treating a suspension of N-dichloroacetyl-DL-serine in anhydrous ether with gaseous hydrogen chloride. The free base, O-dichloroacetyl-DL-serine, is an extremely labile compound and reverts to the N-compound in neutral aqueous solution at room temperature. The hydrochloride salt, however, is stable, in which form it was isolated and characterized. The same compound was prepared from serine and dichloroacetic anhydride in dichloroacetic acid. O-Dichloroacetyl-DL-serine hydrochloride displays an antitumor effect against Sarcoma-37 and Sarcoma-180 in mice. The work has been extended to the monochloro- and trichloro-acetyl derivatives of serine.
THE BASICITIES OF ORTHO-SUBSTITUTED BENZOIC ACIDS
Authors: Stewart Ross , Granger Maurice R.
Published: May 2006

The basicities of 15 ortho-substituted benzoic acids have been measured in sulphuric acid. The ortho effects of alkyl groups are base weakening and increase in the expected order methyl, ethyl, i-propyl, t-butyl. Ortho halo benzoic acids have comparable basicities and are weaker than their para isomers. Oxygen-containing ortho substituents, except hydroxyl, all cause substantial base strengthening relative to the para isomers. Even the groups nitro and carboxyl when substituted ortho in benzoic acid cause the basicity to rise, presumably because of hydrogen bonding in the conjugate acids.
OXIDATION–REDUCTION POLYMERS: I. SYNTHESIS OF MONOMERS
Authors: Spinner I. H. , Yannopoulos J. , Metanomski W.
Published: May 2006

The preparation of two new monomers, 2,5-bis-(2-tetrahydropyranyloxy)-4′-vinyldiphenyl sulphone and 2-tetrahydropyranyl-4′-vinylphenyl thioether, for the synthesis of redox polymers is described.
SANDARAC ACIDS: 6β-HYDROXYSANDARACOPIMARIC ACID
Authors: ApSimon J. W. , Edwards O. E.
Published: May 2006

The resin from Callitris quadrivalvis Vent. Decad. (Sandarac resin) has been shown to contain 6β-hydroxysandaracopimaric acid (6β-hydroxy-7-epipimara-9(14),19-dienoic acid).
THE CONSTITUTION OF A HEMICELLULOSE OF CHERRY WOOD (PRUNUS AVIUM L. VAR. BING)
Authors: Dutton G. G. S. , McKelvey Shirley A.
Published: May 2006

The hemicellulose isolated by direct alkaline extraction of the wood has been shown to be a 4-O-methyl-D-glucuronoxylan. Methylation data indicate a backbone of approximately 110 D-xylopyranose units linked by β, 1 → 4 bonds with single units of 4-O-methyl-D-glucuronic acid linked by α, 1 → 2 bonds. The proportion of acid units to xylose is approximately 1:7. 2,3-Di-O-methyl-D-lyxose was isolated as an artifact.
STERIC CONFIGURATION OF THE ETHER GROUP IN ORTHO ALKOXY AND ARYLOXY BENZOIC ACIDS
Authors: Wheeler Owen H.
Published: May 2006

not available
VOLATILITY OF CUPRIC NITRATE
Authors: Pittwell L. R.
Published: May 2006

not available
CONSTITUTION OF AN ALDOTETRAOURONIC ACID FORMED ON ENZYMIC HYDROLYSIS OF A 4-O-METHYLGLUCURONOXYLAN FROM THE WOOD OF WHITE BIRCH (BETULA PAPYRIFERA MARSH.)
Authors: Timell T. E.
Published: May 2006

An aldotetraouronic acid has been isolated by enzymic hydrolysis of a 4-O-methylglucuronoxylan from the wood of white birch. It has been shown to be O-4-O-methyl-α-D-glucosyluronic acid-(1 → 2)-O-β-D-xylopyranosyl-(1 → 4)-O-β-D-xylosyl-(1 → 4)D-xylose.
METAL OXIDE ALKOXIDE POLYMERS: PART IV. THE HYDROLYSIS OF SOME TANTALUM ALKOXIDES
Authors: Bradley D. C. , Holloway H.
Published: May 2006

Ebulliometric studies on the hydrolysis of tantalum pentaalkoxides Ta(OR)5, where R = Me, Prn, Bun, and Bus, have furnished important data on the polymeric nature of tantalum oxide alkoxides. It is shown from the variation of number-average degrees of polymerization as a function of degree of hydrolysis that the polymers conform to certain structural models. The structural models involve 6-co-ordinated tantalum.
THE INFRARED FREQUENCIES AND INTENSITIES OF THE HYDROXYL BAND OF ORTHO-ALKYL PHENOLS IN THE VAPOR PHASE
Authors: Ingold K. U.
Published: May 2006

The infrared frequencies and intensities of the fundamental stretching vibration of the hydroxyl group have been measured for a number of ortho-alkyl phenols in the vapor phase over a range of temperatures. Both quantities have been shown to depend on internal steric and environmental factors. The differences in enthalpy between the cis and trans isomers of several 2-tert-alkyl phenols have been measured, and it is concluded that the latter are not significantly stabilized relative to the former by solvation in non-polar solvents.
APPARENT DENSITIES AND INTERNAL SURFACE AREAS OF SELECTED CARBON BLACKS
Authors: Walker Jr. P. L. , Kotlensky W. V.
Published: May 2006

It is shown that the open pore volume within carbon blacks can be calculated from nitrogen adsorption isotherms (77°K) on the blacks. From this volume and a helium density, the apparent density of a black can be calculated. Other properties of the blacks which then can be calculated are free surface area, internal surface area, surface roughness factor, and the average pore diameter of the internal surface. These data are presented for five selected carbon blacks.
CHAIN TERMINATION IN THE PHOTOCHLORINATION OF METHYL CHLORIDE
Authors: Mathai K. G. , Roy D. J. Le
Published: May 2006

The photochloriuation of methyl chloride has been studied at 2.4°, 25.0°, and 50.1 °C using absorbed light intensities of the order of 10−10 einstein cm−3 sec−1 and a wave length of 4358 Å. Chain termination was by chlorine atom removal but two mechanisms were operative. For the first, termolecular collisions, the evidence indicated somewhat different third-body efficiencies for methyl chloride, methylene chloride, and chlorine; the efficiency of SF6 was lower than for these by a factor of 6 to 9; the efficiency of HCl was, relatively, too small to measure. The second mechanism involved "sticky" collisions. Methylene chloride was particularly efficient in this process, indicating an unusually stable CH2Cl2–Cl complex.
AMINO ACIDS: X. PREPARATION AND CHEMISTRY OF 2-(ω-CARBOXYALKYLAMINO)-DIHYDROTHIAZINES, -TETRAHYDROPYRIMIDINES, AND -IMIDAZOLINES
Authors: McKay A. F. , Kreling M.-E.
Published: May 2006

The preparation and properties of 3-keto-1,2,5,6-tetrahydro-3(H)-imidazo(1,2-a)imidazole, 3-keto-1,2,6,7-tetrahydro-3(H),5(H)-imidazo(1,2-a)pyrimidine, and 4-keto-2,3,6,7,8,9-hexahydro-4(H)-pyrimido(1,2-a)pyrimidine are described. The first two bicyclic systems possess active methylene groups in position 2 and they are oxidized to indigo-type dyes.
THE CONFIGURATION OF GLYCOSIDIC LINKAGES IN OLIGOSACCHARIDES: X. KÖNIGS–KNORR REACTIONS OF 3,5-DI-O-BENZOYL-ARABINO- AND -RIBO-FURANOSYL BROMIDES AND THEIR 2-SUBSTITUTED DERIVATIVES
Authors: Gorin P. A. J.
Published: May 2006

The reactions of 3,5-di-O-benzoyl-L-arabinofuranosyl and -D-ribofuranosyl bromides and their 2-substituted 1,2-trans-derivatives (2-acetates, 2-benzoates, 2-p-nitrobenzoates, and 2-nitrates) with methanol and 1,2,3,4-tetra-O-acetyl-β-D-glucose have been studied. The products of these reactions, the occurrence of retention or inversion of configuration or orthoester formation, and the suitability of bromo derivatives for stereospecific synthesis of glycosidc linkages were considered. In general, the syntheses of oligosaccharides are more stereospecific than the corresponding formation of methyl glycosides. As in the α-D-mannopyranosyl bromide series, the reactions with tetra-O-acetyl-glucose give products with retention of configuration about C-1, presumably via an intermediate cyclic carbonium ion when there is an ester at C-2, but retention can take place also even when there is no convenient ester group at C-2 of the bromide. The participation of the C-2 substituent is particularly noteworthy in the condensations of the 2-acetate and 2-benzoate derivatives of 3,5-di-O-benzoyl- β-D-ribofuranosyl bromide with 1,2,3,4-tetra-O-acetyl–β-D-glucose, which yield exclusively disaccharides of the orthoester type.
CHEMISTRY OF THE TRIFLUOROMETHYL GROUP: PART IV. DIPHENYLTRIFLUOROMETHYLPHOSPHINE AND COMPLEX FORMATION BY PHENYLTRIFLUOROMETHYLPHOSPHINES
Authors: Beg M. A. A. , Clark H. C.
Published: May 2006

Three methods of preparing diphenyltrifluoromethylphosphine are described. The hydrolysis of the phosphine to diphenylphosphinic acid and fluoroform, and the formation of dibromo-and diiodo-phosphoranes from the phosphine are reported. The adducts (C6H5)3P•BF3 and (C6H5)2CF3P•BF3 are described and the latter is found to be the less stable. With platinum (II) chloride, the complexes trans-[(C6H5)2PCF3]2PtCl2 and trans-[C6H5PCF3)2]2PtCl2 are formed. The properties of the BF3 adducts and PtCl2 complexes are interpreted in terms of the electronegativity and size of the trifluoromethyl group.
PREPARATION OF ALUMINUM tert-ALKOXIDES
Authors: Bains M. S.
Published: May 2006

not available
THE THERMOSIPHON AS A SIMPLE CIRCULATING PUMP FOR GASES
Authors: Auwera D. der , Back R. A.
Published: May 2006

not available
CHEMISTRY OF THE TRIFLUOROMETHYL GROUP: PART V. INFRARED SPECTRA OF SOME PHOSPHORUS COMPOUNDS CONTAINING CF3
Authors: Beg M. A. A. , Clark H. C.
Published: May 2006

The infrared spectra of several series of trifluoromethyl-phosphorus compounds are correlated, the compounds examined being the iodides CF3PI2 and (CF3)2PI, the methyl-trifluoromethyl-phosphines of the general formula (CH3)nP(CF3)3−n, where n = 1, 2, or 3, and the analogous phenyl-trifluoromethyl-phosphines. Satisfactory assignments are made for the majority of absorption bands in the 650–4000 cm−1 region. The infrared spectra of some phosphine – boron trifluoride adducts are also examined and assignments of the principal bands are made.
IONIZATION OF ORGANIC COMPOUNDS: II. THIOACETAMIDE IN AQUEOUS SODIUM HYDROXIDE. THE H−ACIDITY FUNCTION
Authors: Edward J. T. , Wang I. C.
Published: May 2006

The ionization ratio of thioacetamide in aqueous sodium hydroxide, determined spectrophotometrically, is proportional to the concentration of hydroxide ion up to a concentration of about 1 M, and indicates a pKHAof 13.4. For more concentrated solutions the ionizing power increases more rapidly than the hydroxide ion concentration; from the experimentally determined ionization ratios the values of the h−acidity function for 1–6 M sodium hydroxide have been calculated. The relation of h−values to the salting-out parameters and water activities of concentrated sodium hydroxide solutions is discussed.
THE PROTON MAGNETIC RESONANCE SPECTRUM OF 1-FLUORO-2,4-DINITROBENZENE
Authors: Schaefer T.
Published: May 2006

A reliable analysis of the proton resonance spectrum of 1-fluoro-2,4-dinitrobenzene is described. Solvent effects were used to obtain this analysis and a possible source of error in a previous analysis is indicated. Spectra parameters are also derived for 1,5-difluoro-2,4-dinitrobenzene. The spectrum of the latter compound confirms the assignment of peaks in the spectrum of the former.
PHOTOLYSIS OF NITRATE ESTERS: PART I. PHOTONITRATION OF DIPHENYLAMINE
Authors: Hayward L. D. , Kitchen R. A. , Livingstone D. J.
Published: May 2006

The photolysis of nitrate esters dissolved in benzene or ethanol or absorbed on filter paper occurred readily under illumination in the 265 mμ to 334 mμ spectral region. Equimolar amounts of 1,4;3,6-dianhydro-D-glucitol-2,5-dinitrate and diphenylamine dissolved in absolute ethanol or benzene did not react in the dark at 25°. Irradiation of the nitrogen-purged solutions for 2 hours at 15° with a mercury arc followed by chromatographic separation yielded 2-nitro-, 4-nitro-, N-nitroso-, and 4-nitroso-diphenylamine together with about 4% unreacted diphenylamine and an unidentified mixture of more polar compounds. In a partial fractionation of the aromatic photoproducts approximately 80% of the original diphenylamine was recovered in the form of the monosubstituted derivatives which contained about 37% of the original ester nitrogen as C-nitro groups and 2 to 3% as C- and N-nitroso groups.Possible mechanisms of the photonitration are discussed.
ON THE MECHANISM OF DISSOLUTION OF MAGNESIUM IN AQUEOUS MAGNESIUM CHLORIDE SOLUTIONS: PART II
Authors: Casey E. J. , Bergeron R. E. , Nagy G. D.
Published: May 2006

Measurements have been made of the effect of pressure on the rate of dissolution of Mg at pH 2.0 in two concentrations of aqueous MgCl2. Over the pressure range 0.026–2.5 atmospheres, the rates in 0.3 and 3.0 molal solutions have, respectively, the pressure dependences[Formula: see text]The induction period of the reaction was studied in detail with a sensitive gas-measuring technique. Hydrogen enters the metal in the early stages, to about 1 cc per cc Mg at 27 °C. Its rate of release after the specimen is dried is about five times higher than the rate at which it enters the magnesium.X-Ray diffraction patterns of insoluble reaction products formed on the metal surface after prolonged reaction were examined. Magnesium and magnesium hydroxide are formed in both solutions, while a substantial amount of still unidentified extra solid material (not one of the hydrated hydroxy chlorides) is formed in the 3 molal solution.A mechanism is proposed which describes the pressure measurements quantitatively and is consistent with the other known facts. It involves univalent magnesium as an essential intermediate, the rate being controlled by H2 bubble growth through the gelatinous Mg(OH)2 film, which remains on and protects the surface in 0.3 molal solution, and by bubble nucleation in 3 molal solution, in which the film is complexed away.
LE SPECTRE INFRAROUGE ET LA STRUCTURE MOLÉCULAIRE DE L'ACIDE PERCHLORIQUE ABSOLU
Authors: Giguère Paul A. , Savoie Rodrigue
Published: May 2006

not available
ELEMENTARY PROCESSES IN THE DECOMPOSITION OF OZONE
Authors: McKenney D. J. , Laidler K. J.
Published: May 2006

Potential-energy surfaces are considered for the O4 complex, treated as the three-body complex O … O … O2. By means of these it is shown that O(3P) reacting with O3 may give rise to a molecule of O2 in its ground state and one in any of the states 3Σg− (ground), 1Δg, and 1Σg+; 3Σu+ cannot be produced. Most of the oxygen molecules produced are expected to be in the ground electronic state, but will be vibrationally excited. Such molecules are readily deactivated and unlikely to lead to energy chains by the reaction[Formula: see text]Such chains are therefore unlikely in the thermal decomposition and in that initiated by visible radiation. In ultraviolet light O(1D) atoms are produced and the potential-energy surfaces show that these give rise very efficiently to O(1D) + O3 → O2 + O2(3Σu−); the latter have 141 kcal in excess of the ground state. It is suggested that the subsequent radiative process[Formula: see text]is responsible for sustaining the population of vibrationally excited oxygen molecules in the ground state and that these propagate energy chains, as postulated by McGrath and Norrish (1). The significance of these conclusions is discussed with reference to the experimental evidence.
OCCURRENCE OF LARGE NORMAL SECONDARY INTERMOLECULAR KINETIC ISOTOPE EFFECTS IN NON-EQUILIBRIUM SYSTEMS
Authors: Rabinovitch B. S. , Current J. H.
Published: May 2006

not available
A SYNTHESIS OF ISOASPARAGINE FROM β-BENZYL ASPARTATE
Authors: Benoiton Leo
Published: May 2006

not available
THE EFFECT OF ADDED ELECTROLYTE ON HYDROGEN-BONDING EQUILIBRIUM IN DILUTE SOLUTIONS OF t-BUTYL ALCOHOL IN CARBON TETRACHLORIDE
Authors: Hyne J. B. , Levy R. M.
Published: May 2006

The effect of added tetra-n-butyl ammonium bromide on the hydrogen-bonding equilibrium of t-butyl alcohol in 0.0 to 0.08 M solution in carbon tetrachloride has been studied by infrared investigation of the spectral range 2.5–3.5 μ. The observations have been interpreted in terms of specific interaction between the alcohol and the more polar species of the salt which are present in the complex electrolyte equilibria (for example, ions and ion pairs). It is suggested that these species function as nucleation centers for aggregates of alcohol molecules, the enhanced degree of hydrogen bonding permitted in these aggregates being reflected in the infrared spectral response.
SOME PROPERTIES OF BETA-NITROPROPIONIC ACID
Authors: Unrau A. M.
Published: May 2006

not available
TRANSITION METAL ARSENIDES: V. A NOTE ON THE RHODIUM/ARSENIC SYSTEM AND THE MONOCLINIC DIARSENIDES OF THE COBALT FAMILY
Authors: Quesnel J. Claire , Heyding R. D.
Published: May 2006

not available
STEROIDAL 3-CHLORO-3,5-DIENES
Authors: Deghenghi R. , Gaudry R.
Published: May 2006

not available
COORDINATION COMPOUNDS OF NICKEL (II) PART III. FURTHER MAGNETIC STUDIES OF SOLUTIONS
Authors: Clark H. C. , Macvicar K. , O'Brien R. J.
Published: May 2006

not available
THE CONDUCTANCE OF MOLTEN LITHIUM CHLORATE AND THE EFFECT OF ADDITIONS OF TRACES OF NONELECTROLYTES ON THE CONDUCTANCE
Authors: Campbell A. N. , Kartzmark E. M. , Williams D. F.
Published: May 2006

The specific conductance of pure molten lithium chlorate between 130 and 145 °C was determined and an activation energy of conductance deduced. Additions of substances having various dielectric constants were made to molten lithium chlorate and the conductances determined. These additions were: (a) water, 0–6% by weight; (b) nitrobenzene, 0–0.4% by weight; (c) methyl alcohol, 0–1.25% by weight. The results are discussed.
A NEW PHOTOCHEMICAL REACTION: THE STRUCTURE AND ABSOLUTE STEREOCHEMISTRY OF ATISINE
Authors: ApSimon J. W. , Edwards O. E.
Published: May 2006

Irradiation of azides of diterpenoid acids with 1α- and 1β-carboxyl groups gave the corresponding isocyanates and ca. 25% yields of lactams. The azide of hexanoic acid under comparable conditions gave 8% of hexanamide. The reaction has been used to convert podocarpic acid to the enantiomer of the phenol III derived from atisine. This completes the structure proof of the atisine family of alkaloids, the Garrya alkaloids, and related diterpenes, and proves the absolute stereochemistry of these substances.
HYDRODESULPHURIZATION OF THIOPHENE: III. ADSORPTION OF REACTANTS AND PRODUCTS ON CHROMIA
Authors: Owens P. J. , Amberg C. H.
Published: May 2006

The adsorption of thiophene, butene, hydrogen, and H2S on sulphided chromia was studied by a chromatographic method. Results were similar to those obtained earlier with a cobalt molybdate catalyst (P. J. Owens and C. H. Amberg, Advances in Chem. Ser. No. 33, 182 (1961)), showing strong interaction of the surface with H2 and H2S at reaction temperatures and weaker interaction with thiophene and butene. The main difference lay in the effect of adsorbed H2S on butene hydrogenation, the suppression being far less marked on chromia. Thiophene adsorption or product desorption are unlikely to be rate controlling in the desulphurization reaction, but neither hydrogen adsorption nor surface reaction could be ruled out as possible slow steps.
TOTAL SYNTHESIS OF STEROIDAL DERIVATIVES: I. SYNTHESIS OF HYDROCHRYSENE ANALOGUES AND RELATED COMPOUNDS
Authors: Kutney James P. , McCrae Wm. , By Arnold
Published: May 2006

A synthetic sequence leading to the total synthesis of several hydrochrysene derivatives is described. It is noted that these derivatives may provide entry into the synthesis of various interesting steroidal analogues.
THE ISOLATION OF A REPRESENTATIVE LIGNIN FRACTION FROM WOOD AND STRAW MEALS
Authors: Pepper J. M. , Wood P. D. S.
Published: May 2006

not available
THE DECOMPOSITION OF n-PENTANE SENSITIZED BY ALLYL RADICALS
Authors: Bryce W. A. , Hardiman M. S.
Published: May 2006

not available
POTENTIAL CYTOSTATIC CARBOHYDRATE DERIVATIVES: PART II. N-MUSTARD PHOSPHATES
Authors: Vagi Kitty M. , Adamkiewicz Vincent W. , Nogrady Thomas
Published: May 2006

2,3,4,6-Tetra-O-acetyl-D-glucosyl-(N-bis-β-chloroethyl)-phosphoramidate and ethyl-D-fructopyranoside-1-(N-bis-β-chloroethyl)-phosphoramidate have been synthesized. The first compound inhibited Adenocarcinoma 755 to 40–50%.
THE PREPARATION OF SOME THIOSEMICARBAZONES AND THEIR COPPER COMPLEXES: PART III
Authors: Gingras B. A. , Suprunchuk T. , Bayley C. H.
Published: May 2006

Reactions of some diketones with thiosemicarbazide have been studied under various conditions. Monothiosemicarbazones, dithiosemicarbazones, and cyclization products can be obtained. It was found that dithiosemicarbazones form 1:1 complexes with Cu(II) but failed to react with Cu(I). Dithiosemicarbazones in which the N2-hydrogen atom has been replaced by Me do not form complexes, confirming our views about the importance of this hydrogen atom in the thione ↔ thiol tautomerism necessary for complex formation. 4,4-Dimethyldithiosemicarbazones behave like the unsubstituted parent compounds in forming 1:1 complexes with Cu(II). Infrared spectra provide evidence for the structure of a cyclization product, 5,6-diphenyl-3-thio-1,2,4-triazine, which had been erroneously described by various authors as the thiol tautomer, 5,6-diphenyl-3-mercapto-1,2,4-triazine.
LYCOPODIUM ALKALOIDS: XII. FLABELLIFORMINE
Authors: Curcumelli-Rodostamo M. , MacLean D. B.
Published: May 2006

Evidence is furnished which establishes the structure of a new alkaloid isolated from Lycopodium flabelliforme.
COORDINATION COMPOUNDS OF OLEFINS WITH SOLID COMPLEX SILVER SALTS: I. COORDINATION COMPOUNDS WITH ANHYDROUS SILVER FLUOBORATE
Authors: Quinn H. W. , Glew D. N.
Published: May 2006

Interaction of solid silver fluoborate with the gaseous olefins ethylene, propylene, and the four butenes has been observed to provide 12 new stoichiometric solid coordination compounds (silver fluoborate – olefin complexes) of high stability. Experimental investigation of the univariant pressure–temperature stability lines for the complexes has been made and the thermodynamic functions calculated: the heat content change for complex dissociation is between 9 and 13 kcal/mole of olefin liberated. Infrared spectra of the complexed olefins indicate that the strength of the silver–olefin bond is primarily dependent upon the basicity of the olefin and a comparison of the thermodynamics of dissociation shows anomalous behavior on the part of isobutylene and trans-2-butene as compared with the regularity displayed by the other four olefins.
STEREOCHEMSTRY OF ARSENIC: PART III. o-PHENYLENEDIARSINE OXYCHLORIDE
Authors: Cullen W. R. , Trotter J.
Published: May 2006

Crystals of o-phenylenediarsine oxychloride, C6H4As2Cl2O, are monoclinic with four molecules in a unit cell of dimensions a = 14.50, b = 8.38, c = 7.66 Å, β = 105.8°, space group C2/c. The structure has been determined from projections along the b and c axes. Each molecule is situated on a 2-fold symmetry axis and is planar except for the chlorine atoms, which lie one on either side of the plane of the other atoms. The values of the bond lengths and valency angles have been obtained. Abnormal valency angles at the arsenic and oxygen atoms are the result of their presence in the five-membered ring, and the unusual stability of the molecule in spite of these angles can be interpreted in terms of aromatic character, involving dπ–pπ bonding. The intermolecular separations correspond to normal van der Waals interactions.
VIBRATIONALLY INDUCED PERTURBATIONS IN MOLECULAR ELECTRON DISTRIBUTIONS
Authors: Bader Richard F. W.
Published: May 2006

It is demonstrated that second-order perturbation theory is useful in determining the manner in which the electron density present in a molecule is changed during a nuclear vibration. Furthermore, it is shown that one nuclear motion will lead to a particularly favorable electronic distortion such that this motion is energetically favored over the other possible motions of the molecule. This allows one to employ the theory to predict the symmetry of the reaction coordinate in both unimolecular and bimolecular reactions. The chemical implications of the electron density changes are discussed.
METAL OXIDE ALKOXIDE POLYMERS: PART V. THE HYDROLYSIS OF SOME ALKOXIDES OF TIN (IV), CERIUM (IV), AND URANIUM (V)
Authors: Bradley D. C. , Holloway H.
Published: May 2006

The polymers formed by the hydrolysis of stannic isopropoxide, ceric isopropoxide, and uranium pentaethoxide have been studied by means of an ebulliometric method. The metal oxide alkoxide polymers formed from the tin (IV), cerium (IV), and uranium (V) alkoxides conform to the requirements of a structural theory. In view of the fundamental nature of the theory a formal mathematical presentation is now given.
REACTIONS OF OZONIDES: II. REDUCTIVE AMINATION OF OZONIZATION PRODUCTS WITH ETHANOLIC AMMONIA
Authors: Diaper D. G. M. , Mitchell D. L.
Published: May 2006

Reductive animation of the ozonolysis products of the terminal olefins 10-undecen-1-ol, ethyl 10-undecenoate, 10-undecenoic acid, and 10-undecenamide produces 10-aminodecan-1-ol, ethyl 10-aminodecanoate, 10-aminodecanoic acid, and 10-aminodecanamide respectively. Esters are also formed, in a competitive reaction, by thermal decomposition of the ozonolysis product.
EFFECT OF ADDED AMMONIA ON THE REACTIONS OF ACTIVE NITROGEN WITH CH4, C2H6, AND C2H4
Authors: Wright A. N. , Winkler C. A.
Published: May 2006

The small HCN yield from the CH4 and C2H6 reactions in an unheated, cylindrical reaction vessel is greatly reduced in the presence of added NH3. The addition of NH3 completely quenches the flame emission from the CH4 reaction, and greatly reduces that from the C2H6 and C2H4 reactions. Both flame emission and HCN production from the CH4 and C2H6 reactions appear to be initiated, at reaction temperatures of about 83 °C, by an excited nitrogen molecule similar to that responsible for NH3 decomposition.
CONSTITUENTS OF THE OLEORESIN OF THE MALE FERN (DRYOPTERIS FILIX MAS L.): PART I. ALCOHOL AND STEROL FRACTIONS
Authors: Thomas Telfer Lawson , Taurins Alfred
Published: May 2006

The solid alcohol fraction of the oleoresin of the male fern was shown to contain two higher primary alcohols, 1-tricosano1 and 1-docosanol. The sterol fraction was found by means of chemical and spectrographic evidence to be 5,11(?)-stigmastadien-3β-ol.1-Tricosanol was synthesized from behenic (docosanoic) acid via tricosanoic acid, the latter being the product of Arndt–Eistert synthesis. 1-Docosanol was synthesized by LiAlH4reduction of behenic acid.
COORDINATION COMPLEXES OF METAL ALKOXIDES: PART I. METAL ALKOXIDE – HYDRAZINE COMPLEXES
Authors: Bains M. S. , Bradley D. C.
Published: May 2006

The field of metal alkoxide coordination compounds is surveyed briefly. The preparation of moderately stable complexes of hydrazine with aluminum isopropoxide, titanium ethoxide, titanium isopropoxide, and zirconium isopropoxide is described. Some reactions of these new complexes are reported.
ABSOLUTE YIELDS IN THE γ-RADIOLYSIS OF GASES
Authors: Back R. A. , Woodward T. W. , McLauchlan K. A.
Published: May 2006

Absolute yields of hydrogen from the γ-radiolysis of hydrocarbon gases have been obtained by relating the hydrogen produced to saturation ion currents measured in the radiolysis vessel. Values for [Formula: see text] of 1.28, 1.20, 6.25, 5.40, and 5.00 have been estimated for ethylene, propylene, propane, n-butane, and isobutane respectively. These values are consistently lower than those obtained previously with α-rays, and this is discussed as an effect of radiation quality. Arguments are advanced for the use of M/N, the yield per ion pair, rather than G, as a measure of yields in the radiolysis of gases.
HYDROGEN FORMATION IN γ-IRRADIATED HYDROGEN CHLORIDE
Authors: Armstrong D. A.
Published: May 2006

Hydrogen yields from pure liquid and solid hydrogen chloride irradiated with Co60 γ-rays were [Formula: see text](liquid) = 6.50 ± 0.10 and [Formula: see text] (solid) = 3.30 ± 0.10 at −79 °C and −196 °C respectively. The yield from solid hydrogen chloride was only slightly reduced by the addition of chlorine; but the yield from liquid samples was reduced sharply by low concentrations of chlorine to a value of about 4.5, and then much more gradually by larger concentrations. A [Formula: see text] value of 2.1 persisted at 10 mole% chlorine. The results were interpreted in terms of the formation of hydrogen in the reactions[Formula: see text]and[Formula: see text]Reduction of the hydrogen yields by chlorine was attributed to the reactions[Formula: see text]and[Formula: see text]Values of k11/k15 and k11*/k15* were estimated to be 1.7 × 10−3 and 0.10 respectively, while those of GH and GH(hot) were 2.4 ± 0.2 and 4.0 ± 0.2. Electron scavenging by chlorine was considered as a less likely mechanism for reduction of the hydrogen yield. Sources of the thermal and hot hydrogen atoms were examined and it was suggested that the decomposition of electronically excited molecules might be an important mode of decomposition.
5,6-DIMETHYLBENZ[a]ANTHRACENE AND 5,6-DIMETHYLBENZO[c]PHENANTHRENE
Authors: Bavin P. M. G.
Published: May 2006

5,6-Dimethylbenz[a]anthracene and 5,6-dimethylbenzo[c]phenanthrene have been synthesized, the latter by a novel route.
THE MEASUREMENT OF STREAMING POTENTIALS
Authors: Sims G. H. E. , Gilson R. G.
Published: May 2006

not available
THE CONSTITUTION OF A SYNTHETIC XYLAN: I. GENERAL STRUCTURAL FEATURES
Authors: Dutton G. G. S. , Unrau A. M.
Published: May 2006

The polysaccharide was obtained by polymerization of D-xylose at 140 °C in the presence of phosphorous acid. Complete hydrolysis of the xylan followed by bromine oxidation showed that the synthetic polymer contained only xylose. Periodate oxidation resulted in formation of a considerable quantity of formaldehyde, the origin of which is not known. Periodate oxidation of borohydride-reduced xylan gave additional formaldehyde and, from this, the average D. P. of the polymer was estimated to be about 55. Complete hydrolysis of the polyalcohol gave ethylene glycol, glycerol, and xylose in a ratio of 2:9:1. Partial hydrolysis gave ethylene glycol, glycerol, and at least seven non-reducing components. Hydrolysis of the fully methylated xylan gave tri-, di-, mono-methyl xyloses and xylose in a 32:32:18:5 ratio, and a carbonyl band was evident in the infrared spectrum of the hydrolyzate. No such band was evident in the hydrolyzate of the unsubstituted xylan. The xylan is highly branched and contains some D-xylofuranose units.
RELATIVE SIGNS OF GEMINAL AND VICINAL PROTON–PROTON COUPLING CONSTANTS IN α,β-DIPHENYLPROPIONIC ACID AND ITS METHYL ESTER
Authors: Fraser Robert R.
Published: May 2006

It has been shown that the geminal and vicinal coupling constants are of opposite sign in α,β-diphenylpropionic acid and its methyl ester. The significance of the results is discussed.