bluuebunny/crossref_metadata_2025 huggingface dataset:
LE SPECTRE INFRAROUGE DE L'OZONIDE D'AMMONIUM ET LA STRUCTURE DE L'ION O3−
Authors: Herman Kazimiera , Giguère Paul A.
Published: May 2006

The slow oxidation of solid ammonia by gaseous ozone at low temperature proceeds through an unstable intermediate, ammonium ozonide, after the equation[Formula: see text]The red solid appears on warming around −130 °C, reaches maximum concentration at about −115°, and is all decomposed by −90°. The infrared spectra show, besides the characteristic bands of the NH4+and NO3− ions, two strong bands at 800 and 1 140 cm−1, and two faint ones at 1 260 and 2 053 cm−1 which must belong to the ν2, ν3, ν1and ν1 + ν2 modes of the O3− ion. These frequencies are appreciably higher than the corresponding ones of the ozone molecule, which indicates a stronger bonding in the ozonide ion contrary to most predictions. By analogy with ozone the bond lengths in the ion are estimated to be 1.22 Å and the interbond angle, about 100°.
REACTIONS OF IMINO RADICALS WITH HYDROCARBON GASES
Authors: Brash J. L. , Back R. A.
Published: May 2006

The photolysis of HNCO vapor has been studied in the presence of ethylene, butene, ethane, propane, and neopentane at 51 °C. Both the olefins and paraffins reduced the yield of CO to about one-third of its value in pure HNCO, which is thought to correspond to the CO formed in the primary photolytic step. Yields of N2 and H2 were reduced close to zero in the presence of olefins, and it appears that NH radicals were removed by reaction with olefins. No imines, amines, nor other nitrogenous products could be detected, however, and it is suggested that these were lost by polymerization.Yields of N2 were also reduced close to zero in the presence of paraffins, and it appears that NH reacted readily with the hydrocarbons. Once again, no amines could be detected. The yield of H2, a minor product in pure HNCO, was markedly enhanced, and alkyl radical dimers appeared as products. A mechanism is suggested which involves the decomposition of vibrationally excited amines formed by insertion reactions.
ANTINEOPLASTIC AGENTS: XV. INTRAMOLECULAR REACTIONS OF N-PHENYL-N′-BIS(2-CHLOROETHYL)UREA
Authors: Pettit George R. , Blonda David S. , Upham Roger A.
Published: May 2006

Reaction between phenyl isocyanate and N-bis(2-chloroethyl)amine in cold diethyl ether solution yields N-phenyl-N′-bis(2-chloroethyl)urea. The urea was found to rearrange in ethanol solution or upon warming to, respectively, 2-(N-phenylimino)-3-(2′-chloroethyl)oxazolidine hydrochloride and 1-phenyl-2-oxo-3-(2′-chloroethyl)imidazolidine. Infrared spectral studies, augmented by mass and proton magnetic resonance determinations provided compelling support for the structural formulations. The oxazolidine reaction sequence was also examined employing 4-nitrophenyl isocyanate, 1-naphthyl isocyanate, and N-bis(2-bromoethyl)amine.
LIGHT SCATTERING OF A CRITICAL BINARY LIQUID MIXTURE: TRIETHYLAMINE–WATER
Authors: Chu B. , Kao W. P.
Published: May 2006

The coexistence curve and critical opalescence of a binary liquid mixture, triethylamine–water, have been reinvestigated. The measurements showed that the coexistence curve appears to follow a cubic relation to within about 0.003° of the critical solution temperature, and in this range, there is no evidence of a flat region. Furthermore, within the range of the values of s/λ(where s = 2 sin (θ/2), λ = wavelength in the medium, and s/λ varied from 1.2 × 10−4 to 7.0 × 10−4 Å−1) and temperatures studied, the light scattering data are in good agreement with the Debye theory (J. Chem. Phys. 31, 680 (1959)). The molecular interaction range of Debye was found to be 5.1 ± 0.3 Å.
REACTIONS OF NITRO SUGARS: I. SOME BENZYLIDENE AND ACYL DERIVATIVES OF METHYL 3-DEOXY-3-NITRO-D-HEXOPYRANOSIDES
Authors: Baer Hans Helmut , Kienzle Frank , Neilson Thomas
Published: May 2006

The 4,6-O-benzylidene derivatives VII, VIII, and XVII of methyl 3-deoxy-3-nitro-β-D-mannopyranoside, -β-D-galactopyranoside, and -α-D-glucopyranoside, respectively, were prepared. Acetylation of the β-D-manno derivative (VII) led, depending upon the reaction conditions, to its 2-O-acetate (IX) and, by way of an unexpected epimerization, to the 2-O-acetate (V) of the corresponding β-D-gluco isomer. There is evidence that this epimerization proceeds through methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-erythro-hexopyranos-2-enide (VI). This nitroolefin was obtained by a Schmidt–Rutz reaction from IX (as earlier from V) and was shown to add acetic acid readily giving V. It also added ethanol producing a 2-O-ethyl glycoside (XII). Acetylation of the galacto derivative (VIII) did not afford an acetate but proceeded with dehydration yielding methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-thero-hexopyranos-2-enide (X).A number of further derivatives of methyl 3-deoxy-3-nitro-β-D-glucopyranoside were prepared, viz., the 2-O-acetyl (XI), 2-deoxy-6-O-tosyl (XIV), and 2,6-dideoxy-6-iodo (XV) derivatives.
ADDENDUM: A SIMPLIFIED PROCEDURE FOR THE ANALYSIS OF COMPLEX NUCLEAR MAGNETIC RESONANCE SPECTRA: I. THE PRINCIPLES OF SUB-SPECTRAL ANALYSIS
Authors: Diehl P. , Jones R. G. , Bernstein H. J.
Published: May 2006

not available
HALOGEN ATOM REACTIONS: III. LUMINESCENCE FROM THE RECOMBINATION OF BROMINE ATOMS
Authors: Gibbs D. B. , Ogryzlo E. A.
Published: May 2006

The recombination of bromine atoms has been found to result in the emission of an orange–red glow. Analysis of the banded spectrum has resulted in the identification of the transition responsible for the visible emission as [Formula: see text] The results of a kinetic study of the glow indicate that the emission is second order in [Br] and first order in [Br2]. Several detailed preassociation mechanisms for the reaction are discussed.
THE CHROMIC ACID OXIDATION OF 2-PROPANOL IN TRIFLUOROACETIC ACID
Authors: Lee Donald G. , Johnson Daniel T.
Published: May 2006

The mechanism of the chromic acid oxidation of 2-propanol in trifluoroacetic acid solutions has been studied. The general features of this reaction strongly resemble those observed in aqueous solutions of other strong acids. A "normal" primary kinetic isotope effect is observed, similar thermodynamic parameters are obtained, and the rate behaves in similar way towards changes in acidity.An extensive study of the effect of added salts on this reaction has substantiated that the identity of added anions has a profound effect on the rate of reaction and that any complete reaction mechanism must take this into consideration.
THE FLOW OF GASES THROUGH MICROPOROUS CARBON
Authors: Bartholemew R. F. , Flood E. A.
Published: May 2006

Steady state flow rates are reported for He, Ar, N2, Kr, methane, propane, and n-butane flowing through a microporous carbon rod at room temperature.
THE REACTIONS OF 2-METHYL ETHYLENIMINE AND AZACYCLOBUTANE WITH ATOMIC HYDROGEN
Authors: Jamieson J. W. S. , Brown G. R. , Hancock W. K.
Published: May 2006

The reactions of hydrogen atoms with 2-methyl ethylenimine and azacyclobutane have been investigated at various temperatures. Between 100 and 300 °C both reactions have been found to be rapid and complete, so that the maximum disappearance of either cyclic imine under these conditions may be regarded as a satisfactory measure of atomic hydrogen flow rates. At 300 °C ethane has been found to be a major product, and it has been inferred from this and other results at this temperature that the other major product of both reactions is cyanogen, which could not be isolated since it appears to form compounds with both cyclic imines.
THE CHEMISTRY OF D-APIOSE: PART II. THE CONFIGURATION OF D-APIOSE IN APIIN
Authors: Hulyalkar R. K. , Jones J. K. N. , Perry M. B.
Published: May 2006

The tri-O-methyl-D-apiose derivative obtained from the hydrolysis products of methylated apiin was found to be identical with 2,3,4-tri-O-methyl-D-apio-D-furanose prepared synthetically. Periodate oxidation studies support the suggested cis relationship of the hydroxyl groups at C2 and C3 of the apiose moiety in apiin, and consideration of optical rotation data suggest that a β-type linkage unites the D-apiosyl unit to C2 of the D-glucopyranose residue in apiin.
Preparation Of 4,4″-Bis(Diphenylamines) By The Chapman Rearrangement
Authors: Barclay Jr. Robert
Published: May 2006

not available
POSSIBLE CALORIMETRIC METHOD FOR MEASUREMENT OF THE LIGAND FIELD SPLITTING ENERGIES FOR THE HEXAAQUO CATIONS OF SOME TRANSITION ELEMENTS
Authors: Jamieson J. W. S. , Brown G. R. , Gruener D. W. , Peiluck R. V. , LaMontagne R. A.
Published: May 2006

High energy modifications of the lower hydrates of the divalent sulfates of manganese, iron, cobalt, and nickel have been prepared by vacuum dehydration. The heats of solution of these materials have been measured and compared with the heats of solution of the normal crystalline lower hydrates. The maximum heats of transition appear to be proportional to the ligand field splitting energies for the corresponding hexaaquo divalent cations, although theoretical justification for this correlation is not yet obvious.
THE MECHANISM OF THE ANOMERIZATION OF THE TETRA-O-ACETYL-D-GLUCOPYRANOSYL CHLORIDES
Authors: Lemieux R. U. , Hayami Jun-Ichi
Published: May 2006

The anomerization of the tetra-O-acetyl-D-glucopyranosyl chlorides in acetonitrile is first order in chloride ion. Experiments with 36Cl-labelled chloride ion showed the reaction to involve nucleophilic attack (SN2) by chloride ion at the anomeric center. The reaction is accompanied by a faster dissociation of the β-anomer (I) to the 1,2-acetoxonium ion. Although the rate of anomerization was slightly accelerated by addition of benzene, the ionic reaction was strongly suppressed. Bromide ion was less effective than chloride ion in catalyzing the reaction and iodide ion was least effective. Reaction of tetra-O-acetyl-α-D-glucopyranosyl bromide with tetraethylammonium chloride in acetonitrile rapidly gave I in high yield. The anomeric effect for chlorine appears to be about 2 kcal/mole.
THE SYNTHESIS OF β-D-GLUCOPYRANOSYL 2-DEOXY-α-D-ARABINO-HEXOPYRANOSIDE
Authors: Lemieux R. U. , Morgan A. R.
Published: May 2006

D-Glucal triacetate reacted with iodonium and bromonium di-sym-collidine perchlorate complexes in the presence of 2,3,4,6-tetra-O-acetyl-β-D-glucopyranose to yield, after deacetylation, crystalline β-D-glucopyranosyl 2-deoxy-2-halogeno-α-D-mannopyranosides. The halogen was hydrogenolyzed catalytically to yield β-D-glucopyranosyl 2-deoxy-α-D-arabino-hexopyranoside (2-deoxy-neotrehalose) isolated as the crystalline heptaacetate. A correction of the literature is made regarding the preparation of "2,3,4,6-tetra-O-acetyl-α-D-glucopyranose".
MECHANISMS FOR THE REACTIONS OF THE ANOMERIC TETRA-O-ACETYL-D-GLUCOPYRANOSYL BROMIDES WITH PYRIDINE AND 2-PYRIDONE
Authors: Lemieux R. U. , Morgan A. R
Published: May 2006

Reaction of tetra-O-acetyl-α-D-glucopyranosyl bromide (I) with pyridine at high dilution gives a high yield of N-(tetra-O-acetyl-β-D-glucopyranosyl)-pyridinium bromide (II). The addition of tetra-n-butylammonium bromide diverts the reaction to the formation of the highly strained α-anomer (III) of II. It is contended that III arises from the β-anomer (IV) of I by way of a rearrangement of an intermediate formed between pyridine and the 1,2-acetoxonium ion (VIII) which readily arises by dissociation of IV. The formation of 2-pyridyl tetra-O-acetyl-α-D-glucopyranoside in >60% yield in the reactions of I with either 2-ethoxypyridine or 2-pyridone in the presence of tetra-n-butylammonium bromide is taken as supporting evidence for this novel type of rearrangement.
THE THERMAL DECOMPOSITION OF METHYL HYDROPEROXIDE
Authors: Kirk Alexander D.
Published: May 2006

The thermal decomposition of methyl hydroperoxide has been studied in solution and in the gas phase. The decomposition was found to be partly heterogeneous in solution in dimethyl phthalate and no reliable rate constants were obtained. Use of the toluene carrier method for the gas phase work enabled measurement of the rate constant for the homogeneous decomposition. The first order rate constants obtained range from 0.19 s−1 at 292 °C to 1.5 s−1 at 378 °C, leading to log A, 11± 2, and activation energy, 32 ± 5 kcal/mole. These results are compared with the expected values of log A, 13–14, and activation energy, 42 kcal/mole. The significance of these findings is discussed.
SYNTHESIS OF 1-ARYL SUBSTITUTED 9H-PYRIDO[3,4-b]INDOLES
Authors: Skinner W. A. , Parkhurst R. M.
Published: May 2006

A series of 1-aryl substituted 9H-pyrido[3,4-b]indoles (1,2,3,4-tetrahydro-β-carbolines) were synthesized by cyclization of tryptamine with a number of substituted benzaldehydes in the presence of hydrochloric acid. Four modifications of reaction conditions were found necessary in order to obtain the desired products containing a variety of substituents on the 1-aryl group. Nuclear magnetic resonance spectra of the products enabled definitive assignment of structure.
REACTIVITIES IN PHOTOSENSITIZED OLEFIN OXIDATIONS
Authors: Kopecky Karl R. , Reich Hans J.
Published: May 2006

The rate of the methylene blue photosensitized oxidation of olefins increases in the order: 1-nonene < 4-methylcyclohexene < cyclohexene < 2,3-dimethyl-1-butene < 2-hexene < cyclopentene < 1-methylcyclohexene < 2,3-dimethylcyclohexene < 1-methylcyclopentene < 1,2-dimethylcyclohexene < 2,3-dimethyl-2-butene. The last compound is oxidized 5 500 times as fast as cyclohexene. Comparison of this reactivity sequence with those obtained in other reactions confirms that the reactive intermediate in the photosensitized oxidations is electrophilic. The relative rates (kA/kB) of photo-oxidation of 1-methylcyclopentene (A) and of 1-methylcyclohexene (B) are 10 and do not vary significantly with five different sensitizers. Thus the same reactive intermediate, presumably singlet oxygen, is formed using each of the five sensitizers.
THE HA ACIDITY FUNCTION AND THE MECHANISM OF AMIDE HYDROLYSIS IN HYDROCHLORIC ACID
Authors: Yates Keith , Riordan J. C.
Published: May 2006

Values of the HA acidity function have been determined for 0–35% hydrochloric acid using a set of amide indicators. The indicator pK values agree with those previously obtained in sulfuric acid. The HA scale decreases less steeply than H0 in the high concentration region, but the difference between the two functions is less marked than in sulfuric acid. The reasons for this are discussed. The values of HA have been combined with available rate and water activity data to obtain information about the mechanism of amide hydrolysis. Eleven sets of rate data, consisting of 64 rate constants obtained under a variety of experimental conditions, give similar hydration parameters for this reaction. The temperature dependence of hydration parameters is discussed.
REACTIONS OF SUGAR CHLOROSULFATES: PART V. THE SYNTHESIS OF CHLORODEOXY SUGARS
Authors: Jennings H. J. , Jones J. K. N.
Published: May 2006

The reaction of sulfuryl chloride with reducing sugars and their methyl glycopyranosides was shown to produce fully substituted pyranose derivatives containing both chlorodeoxy and chlorosulfate ester groups. It was demonstrated that the chlorodeoxy groups were formed by nucleophilic displacement (SN2) by chloride ion of specific reactive chlorosulfate groups in fully chlorosulfated intermediates. The degree of chloro-substitution was shown to be determined by both steric and electronic effects in the individual pyranose derivatives.
CONCERNING THE ORTHO SHIFT IN PROTON AND FLUORINE MAGNETIC RESONANCE OF SOME CONJUGATED HYDROCARBONS
Authors: Hruska F. , Hutton H. M. , Schaefer T.
Published: May 2006

A linear correlation with Q is found for the shifts of protons or fluorines placed ortho or cis to the substituent in monosubstituted benzenes, ethylenes, propenes, monofluorobenzenes, and perfluorobenzenes. The substituent X corresponds to H, F, Cl, Br, I, and Q equals P/Ir3 where P is the polarizability of the C—X bond, r is the C—X bond length, and I is the first ionization potential of atom X. The correlation is useful for predicting some as yet unknown shifts in the above compounds. The significance of this correlation is discussed in an inconclusive manner.
THE EFFECT OF ALPHA AND ALPHA′ DEUTERIUM UPON THE P.M.R. OF 2-BUTANONE
Authors: Tee O. S. , Warkentin J.
Published: May 2006

not available
ORTHO-CHLOROBENZALMALONAMIDE AND RELATED COMPOUNDS
Authors: Mariella Raymond P. , Conway Terry
Published: May 2006

not available
THE CHLORINATION OF MONOFLUOROACETONE WITH SULFURYL CHLORIDE
Authors: Wyman D. P. , Shapiro B. L. , Kaufman P. R.
Published: May 2006

not available
THE ELECTRON SPIN RESONANCE SPECTRUM OF IN γ-IRRADIATED BETAINE
Authors: Drews R. , Cadena Jr. D. , Rowlands J.
Published: May 2006

not available
THERMODYNAMIC EXCESS FUNCTIONS IN THE SYSTEMS ACETIC ACID – WATER AND ACETIC ACID – CHLOROFORM
Authors: Gieskes J. M. T. M.
Published: May 2006

not available
SURFACE EFFECTS IN THE UNINHIBITED AND THE INHIBITED PYROLYSES OF ISOMERIC HEXANES: PART V. 2,2-DIMETHYL BUTANE (NEOHEXANE)
Authors: Chrysochoos J. , Bryce W. A.
Published: May 2006

The rate of pyrolysis of neohexane decreases slightly with increasing S/V ratio in the pressure range of 15–100 mm at 510–530 °C. The yields of CH4, C2H6, and C3H6 increase with increasing hydrocarbon pressure while the yields of i-C4H8 and H2, which increase with increasing hydrocarbon pressure, tend to level off at higher pressures. The rest of the products are pressure independent. The nitric oxide required for maximum inhibition is 12–14 mm for hydrocarbon pressures in the range of 50–120 mm and shifts to slightly higher values for higher S/V ratios. Nitric oxide affects the product distribution slightly. The yields of CH4 and C2H4 increase while the yields of C2H6 and 2-methyl butene-2 decrease with increasing NO pressure. Surface-to-volume (S/V) ratio has no effect on the product distribution in the inhibited pyrolysis of neohexane, indicating the role of the inhibitor to be limited to the gas phase for this isomer. The analytical balance does become less complete with increasing NO pressure because of such reactions as[Formula: see text]
THE PYROLYSIS OF OXIMES OF SOME GAMMA CYANO-AND GAMMA NITRO-KETONES
Authors: Allen C. F. H.
Published: May 2006

Oximes of gamma cyano- and gamma nitro-ketones are decomposed by heat as well as by acids. From the very complex mixtures resulting there have been isolated arylated pyrroles, arylated 2-aminopyridines, and the corresponding pyridones, as well as several minor products. This behavior constitutes a new synthesis of these heterocyclic compounds. In a Beckmann rearrangement γ-benzoyl-α,β-diphenylbutyronitrile gave an anilide, the structure of which was confirmed by an independent synthesis. By physical methods both structures of gamma ketonic amides are confirmed.
SYNTHESIS OF 4-O-β-D-GALACTOPYRANOSYL-D-GALACTOSE
Authors: Curtis E. J. C. , Jones J. K. N.
Published: May 2006

The disaccharide named in the title, 6-O-β-D-galactopyranosyl-D-galactose, and the 2(?)-substituted isomer have been synthesized in low yield by the condensation of acetobromo-D-galactose and di-O-isopropylidene-aldehydo-D-galactose dimethyl acetal.
MASS SPECTRA OF SOME FUROQUINOLINE ALKALOIDS
Authors: Clugston D. M. , Maclean D. B.
Published: May 2006

The mass spectra of six furoquinoline alkaloids have been recorded and mechanisms have been proposed for their fragmentation upon electron impact. Strong metastable peaks, present in all spectra, have aided in the interpretation of the fragmentation of these alkaloids. The three alkaloids with a methoxyl group in the 8-position of the quinoline ring may be differentiated from the other three by the presence of relatively intense peaks at M-1 and M-29.
EFFECT OF WATER VAPOR ON THE FORMATION OF MODIFICATIONS
Authors: Kuntze R. A.
Published: May 2006

The two recognized forms of calcium sulfate hemihydrate can be identified by the position of a relatively small exothermic peak in their differential thermograms. Hemihydrates prepared at various water vapor pressures up to 760 mm Hg were found to produce this exothermic peak in a position which is characteristic for the β-form. These results indicate that α-hemihydrate cannot be made at atmospheric pressure, as was previously suggested on the basis of heat solution measurements. The typical differential thermogram of α-hemihydrate is only obtained with material made by dehydration in solution or by autoclaving. The effect of ambient water vapor pressure on the position of the three peaks that occur in the differential thermogram of CaSO4•2H2O has also been studied. It was found that the incipient temperature of the second endothermic peak, corresponding to the transition of hemihydrate to soluble anhydrite, is displaced independent of the rate of heating from 145 °C to 187 °C with increasing water vapor pressures up to 760 mm Hg. This indicates that, for each temperature, a threshold water vapor pressure exists, above which soluble anhydrite cannot be formed.
THE CHEMISTRY OF THE AMINOCHROMES. PART VIII: THE PREPARATION AND PROPERTIES OF 4- AND 7-METHYLADRENOCHROME
Authors: Heacock R. A. , Hutzinger O.
Published: May 2006

Two new catecholamines, 2- and 5-methyladrenaline, have been prepared from 3-methylcatechol and they gave 4- and 7-methyladrenochrome, respectively, on oxidation. 7-Iodo-4-methyladrenochrome was obtained on oxidation of 2-methyladrenaline with potassium iodate; however, an iodoaminochrome could not be obtained in a similar manner from 5-methyladrenaline. The expected 5,6-dihydroxyindole derivatives were obtained on reduction of these aminochromes.
STEREOSELECTIVE SYNTHESIS OF A DIBENZO[a,g]QUINOLIZINE ANALOG OF 18-HYDROXYEPIALLOYOHIMBANE
Authors: Belleau B. , Puranen J.
Published: May 2006

Starting from cis-Δ4-cyclohexenedicarboxylic acid anhydride, a stereoselective synthesis of cis-Δ4-tetrahydrohomophthalic acid (IX) is described (Chart 1). The synthesis involves selective reduction to Δ4-tetrahydrophthalide (III) and reaction of the latter with cyanide to give miainly the cis-nitrile acid V in good yield. Alkaline hydrolysis leads to the cis-homodiacid IX which was characterized as its corresponding anhydride. The nitrile acid intermediate could be transformed to stereoisomeric decahydroisoquinolines (VIII). Bromolactonization of the cis-diacid IX afforded the bromo-γ-lactone XIII (R = Br; Chart 2) which underwent hydrogenolysis to the already described γ-lactone homoacid intermediate XV in good yield. Transformation of the latter to the dihydroisoquinoline XVIII was uneventful. Reduction with sodium borohydride gave XIX which on heating gave the two isomeric lactams XX and XXII. The former was identical to a lactam already obtained by a different route (ref. 1). The latter was reduced to the tetracyclic base XXIII which is believed to exist in conformation XXIVc. The corresponding trimethoxybenzoic acid ester was prepared and tested for reserpine-like activity. It was found to be inactive. The significance of this result is briefly discussed.
NUCLEAR MAGNETIC RESONANCE SPECTRA AND CONDUCTIVITIES OF SOME METAL ACETYLACETONATES
Authors: Carty A. J. , Tuck D. G. , Bullock E.
Published: May 2006

Chemical shift data and conductivities of acetylacetonates of some group IA, IIA, and IIIA metals in dimethylsulfoxide are recorded. It is concluded that nuclear magnetic resonance spectra cannot give definite information on π-bonding in these complexes, though the results for the group III elements are consistent with the presence of such bonds, as is the evidence from related spectroscopic studies.
FATTY ACIDS OF CATALPA BIGNONIOIDES AND OTHER BIGNONIACEAE SEED OILS
Authors: Chisholm Mary J. , Hopkins C. Y.
Published: May 2006

Seed oils of 11 species of Bignoniaceae, representing four of the five tribes of the family, were analyzed by gas–liquid chromatography and other techniques. The fatty acids of Catalpa bignonioides oil had the following composition: trans-9,trans-12-octadecadienoic 5, trans-9,trans-11,cis-13-octadecatrienoic 31, palmitic 5, stearic 1, octadecenoic 8, linoleic 50%. One of the five samples of this species showed evidence of an appreciable amount of conjugated dienoic acid.Jacaranda semiserrata had 33% of a cis,trans,cis trienoic acid. Kigelia pinnata had 57% of a non-conjugated trienoic acid. The other eight species had the ordinary palmitic–oleic–linoleic composition. The total fatty acid composition of the oils is reported.The tribe Tecomeae yielded both conjugated and non-conjugated seed oils. Single species of each of the other three tribes gave non-conjugated oils.
SOLVENT EFFECTS IN THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF BENZALMALONONITRILES
Authors: Weinberger M. A. , Heggie R. M. , Holmes H. L.
Published: May 2006

The nuclear magnetic resonance spectra of a series of substituted benzalmalononitriles were examined in various solvents. The chemical shifts for the olefinic protons are susceptible to large solvent effects which are interpreted as arising from association of a solvent molecule with the olefinic proton (acetone) or a site in its vicinity (benzene). With acetone this leads to a downfield shift from values observed in chloroform. In benzene solution the association produces increased shielding and is present in addition to a second solvation complex, the arrangement of which is governed by the substituent. The difference in behavior of the ethylenic proton in benzalmalononitriles from the formyl proton in benzaldehyde is ascribed to its more highly acidic nature.
CEANOTHUS ALKALOIDS: I. ISOLATION, SEPARATION, AND CHARACTERIZATION
Authors: Warnhoff E. W. , Pradhan S. K. , Ma J. C. N.
Published: May 2006

Five pure alkaloids have been separated from the crude mixture of Ceanothus americanus (Rhamnaceae) bases by means of column and thick-layer chromatography. Their molecular formulas have been established as C30H40O4N4, C29H36O4N4, C26H38O4N4, and C28H44O4N4 (two compounds). One of these may be identical with the previously reported ceanothine. Evidence is presented for the functional groups and other features of the molecules.
Cis–trans ISOMERISM IN 2-ARYLIDENE-3,3-DIPHENYLINDAN-1-ONES
Authors: Bevan J. A. , Gagnon P. E. , Rae I. D.
Published: May 2006

not available
SOME COMMENTS ON CRAIG'S RULES
Authors: Abramovitch R. A. , McEwen K. L.
Published: May 2006

not available
REACTION OF AMINES WITH DIMETHYLTHIOFORMAMIDE
Authors: Pettit George R. , Garson Lorrin R.
Published: May 2006

not available
NUCLEAR MAGNETIC RESONANCE SPECTRAL OBSERVATIONS ON THE GLYCOL-SCISSION OF DEUTERATED D-GLUCOSE
Authors: Mackie W. , Perlin A. S.
Published: May 2006

The positions of formyl ester groups in products obtained on oxidative glycol-scission of specifically deuterated D-glucose and its 3-O-methyl ether have been determined by n.m.r. spectroscopy. These structural assignments are based on the effect of deuteration on the signal given by the proton located α to the formyloxy group in the undeuterated compound. Thus, mono-O-formyl-2-O-methyl-D-arabinose-4-d (IV) produced by lead tetraacetate oxidation of 3-O-methyl-D-glucose-5-d (I) shows a modified resonance signal for this proton, whereas the signal is absent from the spectrum of the monoformate (III) obtained by periodate oxidation of I. Therefore, IV is a 3-formate and III a 4-formate. According to these findings a furanose form (II) of I is involved in the lead tetraacetate reaction, whereas periodate degrades the pyranose form of the sugar directly.Oxidation of D-glucose-6,6′-d2 with lead tetraacetate is shown in similar fashion to yield 2,3-di-O-formyl-D-erythrose-4,4′-d2, evidence that this degradation involves two successive pyranose-to-furanose interconversions.The preparation of I, and of some other derivatives of D-glucose-5-d, is described.
PERMANGANATE–PERIODATE OXIDATION: PART VII. THE OXIDATION OF SOME ACYCLIC MONOTERPENES
Authors: Rudloff E. Von
Published: May 2006

The reaction of permanganate–periodate with 1-decene and 1-octadecene in aqueous suspension or media containing tert-butanol has been studied. C10-compounds are oxidized almost quantitatively with the aqueous reagent. Myrcene, cis-ocimene, citronellol, citronellal, citronellic acid, geraniol, nerol, linalool, and linalyl acetate are all oxidized in high yield to the predicted products. These can serve conveniently for chemical identification of the aliphatic terpenes when isolated from mixtures by gas–liquid chromatography. The reaction may also be useful in locating the 14C-label in tracer studies.
THERMODYNAMIC FUNCTIONS OF THE PARTIALLY DEUTERATED METHYL HALIDES AS ANHARMONIC OSCILLATORS
Authors: Riter Jr. John R. , Goldberg Marvin C.
Published: May 2006

By determination of the diagonal anharmonic constants xii in the expression for vibrational terms as a power series in the vibrational quantum numbers, the rigid-rotor anharmonic oscillator thermodynamic functions of the eight partially deuterated methyl halides (CH2DX and CHD2X, X = F, Cl, Br, I) have been computed. The effects of omission of the cross terms xii is discussed. From the computed xii, the calculated positions of 23 combination bands were found to have a mean deviation of 0.3% above the observed values, and the calculated positions of 11 first overtone bands had a mean deviation of 2.7% below the corresponding observed values. Tables.of −(F0 – E00)/RT, (H0 – E00)/RT, S0/R, and Cp0/R for the anharmonic case and Cp0/R for the harmonic case at 100 deg intervals between 100 and 1 500°K, and thence in 500 deg intervals to 3 000 °K, have been made available. Tables of observed fundamental frequencies, anharmonicity constants xii, and moments of inertia for all molecules are included. A comparison of differences in each of the four thermodynamic functions for the anharmonic and harmonic cases is given for 1 000 and 3 000°K. The maximum differences in Cp0 and S0 occur for CHD2Cl and amount to 0.50 and 2.08 (Cp0), and 0.10 and 0.36 (S0) cal/mole deg at 1 000 and 3 000°K respectively, with the anharmonic values always larger.
PHOTOCHEMISTRY OF ELECTRONS TRAPPED IN GLASSES OF METHYLTETRAHYDROFURAN AT 77°K
Authors: Dyne P. J. , Miller O. A.
Published: May 2006

In the radiolysis of methyltetrahydrofuran glass at 77°K electrons are produced with a high yield. These are immobilized in traps in the glass and do not recombine with positive ions. They can be released from their traps by illumination with visible and infrared light and may then diffuse to positive ions and be captured. The quantum efficiencies for bleaching have been measured as a function of wavelength. This quantum efficiency falls as bleaching proceeds and depends on the fraction of the electrons bleached and not on their concentrations. About half the electrons are trapped close to positive ions and, on release, have a high probability of diffusing to the positive ion. The remaining half are trapped homogeneously. On release from their traps, few of these electrons reach positive ions although they diffuse over long distances before being retrapped in the glass. This behavior is compared to that discussed by Samuel and Magee for the thermalization and capture of electrons in liquid water.
ABSOLUTE RATE CONSTANTS FOR HYDROCARBON AUTOXIDATION: II. DEUTERO STYRENES AND RING-SUBSTITUTED STYRENES
Authors: Howard J. A. , Ingold K. U.
Published: May 2006

The effect of deuterium substitution on the absolute rate constants for the bimolecular chain termination process in the oxidation of styrene indicates that the α-hydrogen is abstracted in this reaction. The first order chain termination process is suppressed both by deuteration of styrene at the α-position and by the addition of heavy water. A possible mechanism for this termination is proposed. There appear to be small secondary deuterium isotope effects in the propagation reaction.The overall oxidation rates and the propagation rate constants are increased by the addition to the aromatic ring of both electron-attracting and electron-releasing substituents. This is attributed in the former case to the increased stability of the resulting styryl radicals and in the latter case to the increased stability of a dipolar transition state. In hydrogen atom abstraction from 2,6-di-t-butyl-4-methylphenol, the peroxy radical from 3-chlorostyrene is more reactive than that from styrene which, in turn, is more reactive than the peroxy radical from 4-methoxy-styrene.
STRUCTURES OF MERCURY MERCAPTIDES: PART II. X-RAY STRUCTURAL ANALYSIS OF MERCURY ETHYLMERCAPTIDE
Authors: Bradley D. C. , Kunchur N. R.
Published: May 2006

The unit cell parameters for Hg(SC2H5)2 were determined by X-ray diffraction: a = 7.54 ± 0.02; b = 4.87 ± 0.01; c = 23.80 ± 0.04 Å; β = 85°. The unit cell contains four formula units, and a complete structural analysis revealed a molecular lattice with insignificant intermolecular bonding involving mercury and sulfur. Interatomic distances (excluding C—H) were determined.
THE STEREOCHEMISTRY OF THE TETRAHYDROPIMARIC ACIDS
Authors: ApSimon J. W. , Demarco P. V. , Lemke J.
Published: May 2006

Evidence is presented that the fully reduced derivatives of pimaric acid (I), sandaracopimaric acid (II), and isopimaric acid (III) have trans–anti–trans fused skeletons. The implications of this observation are discussed.
COORDINATION COMPOUNDS OF OLEFINS WITH ANHYDROUS SILVER SALTS: II. AN INFRARED AND NUCLEAR MAGNETIC RESONANCE INVESTIGATION OF SILVER TETRAFLUOROBORATE - OLEFIN COMPLEXES
Authors: Quinn H. W. , McIntyre J. S. , Peterson D. J.
Published: May 2006

A determination has been made of the changes which occur in the infrared and proton magnetic resonance spectra of a number of olefins when they form AgBF4•2 olefinates. The data obtained indicate that: (i) asymmetric substitution at a double bond results in nonsymmetric orientation of the silver ion relative to the trigonal carbon atoms and to the plane of the pi orbital; (ii) complexing may affect the rotation about the bond between a secondary or tertiary tetrahedral carbon and a trigonal carbon in order to reduce interaction between the two olefin molecules; (iii) in the solid state, lattice restrictions can result in interaction between the two olefin molecules.
THE YIELD OF SINGLET OXYGEN IN THE REACTION OF CHLORINE WITH HYDROGEN PEROXIDE
Authors: Browne R. J. , Ogryzlo E. A.
Published: May 2006

not available
SPECTROSCOPIC STUDIES OF ALCOHOLS: VI. INTRAMOLECULAR HYDROGEN BONDS IN ETHANOLAMINE AND ITSO- ANDN-METHYL DERIVATIVES
Authors: Krueger P. J. , Mettee H. D.
Published: May 2006

The competitive intramolecular [Formula: see text] hydrogen bonding in ethanolamine and N-methylethanolamine has been studied in dilute C2Cl4solution by means of the temperature dependence of the fundamental OH and NH stretching bands. Of the three conformers identified for each of these compounds, the least stable shows a distinct band which is assigned to a "terminal" OH group involved in an intramolecular [Formula: see text] hydrogen bond. Enthalpy differences between conformers are reported and discussed, and compared with those found for the conformational equilibria in 2-methoxyethylamine and N,N-dimethyl-ethanolamine.
THERMAL STABILITY OF AN ADSORBED ARRAY OF CHARGES IN THE EINSTEIN APPROXIMATION
Authors: Macdonald J. Ross , Barlow Jr. C. A.
Published: May 2006

For an infinite hexagonal array of ions adsorbed on a conducting plane of infinite extent, the thermal fluctuation from strict lattice ordering in the neighborhood of a given adion is considered. The ions are imaged in the uniform, conducting adsorbent and are assumed to move freely in the plane; they thus arrange themselves in a perfect hexagonal array at absolute zero temperature. By use of the accurate planar potential seen by one adion moving in the field arising from an infinite number of fixed hexagonally arrayed surrounding ions, the root-mean-square (r.m.s.) amplitude of planar vibration of the ion relative to its neighbors is approximately determined for several values of nearest neighbor distances between ions, r1. On the basis of these results, we find, for example, that for a distance, β, between the center of charge of an ion and the imaging plane of 3 Å, an ionic valence zv of unity, and an effective dielectric constant of ε, a hexagonal array with r1 = 15 Å is stable up to a temperature, T0, of approximately 1760/ε°K while one with r1 = 21 Å is stable up to about 760/ε°K. Results apply to adsorption from either a gas or liquid phase and, as well, to an array of real dipoles adsorbed on a nonconducting surface. The appropriate values for ε are of the order of 2 and 6, respectively, for adsorption from gas or from aqueous electrolytes. For various r1's, explicit expressions for T0 are obtained which depend on ε, β, and zv.
TERPENOIDS: XIII. THE STEREOCHEMISTRY OF CHAPARRIN, CHAPARROL, AND RELATED COMPOUNDS
Authors: Hollands T. R. , Mayo P. De , Nisbet M. , Crabbé P.
Published: May 2006

Evidence is presented which leads to the absolute stereostructures XX, X, XI, and XII for chaparrin, chaparrol, isochaparrol, and neochaparrol respectively. The absolute configuration is arrived at by conversion to an optically active biphenyl (dihydrophenanthrene).
SOME HEATS OF SOLUTION IN LIGHT AND HEAVY WATER
Authors: Davies D. H. , Benson G. C.
Published: May 2006

not available
ACYLGUANIDINES AS INTERMEDIATES IN PEPTIDE SYNTHESES
Authors: Hoffmann Eliahu , Diller Dov
Published: May 2006

not available
THE CHROMIC ACID OXIDATION OF ARYL TRIFLUOROMETHYL ALCOHOLS: ISOTOPE AND SUBSTITUENT EFFECTS
Authors: Stewart Ross , Lee Donald G.
Published: May 2006

not available
STRUCTURE VIBRATIONNELLE DES SPECTRES D'ABSORPTION DANS L'ULTRAVIOLET DE QUELQUES DÉRIVÉS HALOGÉNÉS DU BENZÈNE
Authors: Pesteil P. , Shurvell H. F. , Pesteil L.
Published: May 2006

Ultraviolet absorption spectra have been recorded, at low temperatures, for pure crystals of the following compounds: hexachlorobenzene, o, m, and p-dichlorobenzenes, o, m, and p-dibromobenzenes, 1,2,3-trichlorobenzene, and 1,2,4,5-tetrachlorobenzene. In all cases, the first electronic transition corresponding to the 1B2u−1A1g transition of benzene has been studied. For six of these compounds the spectra were sufficiently well resolved to permit complete analyses of the vibrational fine structure of the electronic bands. The results indicate that only totally symmetrical vibrations appear in conjunction with the observed electronic transitions. Several changes in published vibrational assignments are proposed, in the light of present results.
OCCURRENCE IN SEED OILS OF SOME FATTY ACIDS WITH CONJUGATED UNSATURATION
Authors: Hopkins C. Y. , Chisholm Mary J.
Published: May 2006

The following fatty acids were identified in the respective seed oils; α-eleostearic in Kentranthus macrosiphon; trans-8,trans-10,cis-12-octadecatrienoic in Osteospermum hyoseroides; 9-hydroxy-10,12- and 13-hydroxy-9,11-octadecadienoic in Tagetes erecta. Dimorphecolic acid was obtained from Osteospermum ecklonis in pure crystalline form. It gave 9-D-hydroxystearic acid on hydrogenation, thus establishing the D-configuration of the parent acid. Dehydration of dimorphecolic acid gave a mixture of all-trans-8,10,12- and all-trans-9,11,13-octadecatrienoic acids.
INFRARED STUDY OF THE PHOTOCHEMISTRY OF TETRAMETHYLCYCLOBUTAN-1,3-DIONE
Authors: Haller Ivan , Srinivasan R.
Published: May 2006

The photolysis of tetramethylcyclobutan-1,3-dione was investigated in a nitrogen matrix at 4°K and in solution in cyclohexane at room temperature. Infrared spectra of the reactant after irradiation showed the formation of carbon monoxide, dimethylketene, tetramethylethylene, and a compound with an intense absorption at 1 840 cm−1 which has been identified as tetramethylcyclopropanone. Since the dimethylketene that was formed was also capable of undergoing secondary photolysis, the effect of light (mainly 2 537 Å) on dimethylketene in solution or in a nitrogen matrix, was also studied. It has been found that in solution 0.2 of the molecules of tetramethylcyclobutandione which decompose, do so to give two molecules of dimethylketene, while approximately the same number of molecules decompose to tetramethylcyclopropanone and carbon monoxide. The remainder of the molecules seem to give tetramethylethylene and carbon monoxide in a concerted process.
ORTHO PARTICIPATION IN THE CONVERSION OF syn-BENZALDOXIME ESTERS TO NITRILES
Authors: Crawford Robert J. , Woo Charles
Published: May 2006

Substituted syn-benzaldoxime esters are transformed, in an alcoholic solution, to the corresponding nitriles according to first-order kinetics. All ortho substituents were observed to accelerate the rate of nitrile formation relative to the corresponding para derivative. While the ko/kp ratios for the bromo, chloro, fluoro, methoxy, and methyl substituents fall within the range of 2 to 9, the iodo and methylthio substituents are 119 and 11 000 respectively. Isotopic replacement of the aldoximino hydrogen by deuterium gives rise to a kinetic isotope effect, kH/kD being 5.21 for syn-o-chlorobenzaldoxime p-toluenesulfonate, 1.22 for syn-o-iodobenzaldoxime p-toluenesulfonate, and 1.23 for syn-o-methylthiobenzaldoxime o-iodobenzoate. The marked enhancement of rate and the absence of an appreciable isotope effect are considered to be associated with sulfur and iodine participation in the rate-determining step. A mechanism which is capable of explaining the results observed is suggested.
ALICYCLIC KETYLS: II. TEMPERATURE DEPENDENCE OF THE CONFORMATIONAL MOBILITY OF MEDIUM-SIZED RINGS
Authors: Lown J. W.
Published: May 2006

The electron paramagnetic resonance spectra of ketyls derived from alicyclic ketones containing from 6 to 12 carbons have been recorded in 1,2-dimethoxyethane or dimethoxymethane at temperatures from −96 to +87 °C. At −96° individual conformers of the cyclohexyl ketyl are observed with hyperfine couplings in close agreement with that of the conformationally 'frozen' 4-tert-butyl analogue at room temperature. The cycloheptyl ketyl conformational equilibrium between forms which have a plane of symmetry through the C—O bond axis is 'frozen' with respect to the spectrometer frequency at temperatures from −40 to +88 °C. Cyclooctyl ketyl equilibrates at ordinary temperatures between two conformers lacking a plane of symmetry through the C—O bond axis. The electron paramagnetic resonance spectra of the ketyls derived from 10- and 12-membered rings show dramatic temperature dependence, which is interpreted in terms of two or more simultaneous conformational equilibria. Values for the dihedral angles of the alpha protons and for the spin density on the sp2 carbon are derived.
ÉTUDES CONFORMATIONNELLES EN SÉRIE CYCLOPENTANIQUE: I. LA TERT-BUTYL-3 CYCLOPENTANONE ET SES DÉRIVÉS
Authors: Richer Jean-Claude , Gilardeau Claude
Published: May 2006

not available
QUINOXALINE DERIVATIVES: VIII. THE EFFECT OF ELECTRON-DONATING GROUPS ON THE FORMATION OF CERTAIN QUINOXALINECARBOXYANILIDE N-OXIDES AND THEIR REARRANGEMENT
Authors: Ahmad Yusuf , Habib M. S. , Iqbal M. , Qureshi M. Ikram
Published: May 2006

Introduction of methyl or methoxy groups into the benzene ring of quinoxalinecarboxyanilide (Id), makes the resulting anilides less prone to "abnormal" oxidation (1). Normal N-oxides (IIf and IIj) were obtained from the anilides If and Ij in which the cyclic [Formula: see text] was unprotected. The methyl-substituted anilides Ig and Ih, however, on oxidation with peracetic acid gave the hydroxy derivatives (Vg and Vh) instead of the N-oxides (IIg and IIh). The methoxy-substituted anilides Ik and Il did not give the hydroxy derivatives Vk and Vl nor the expected N-oxides IIk and IIl. All the N-oxides (IIe, IIf, IIi, and IIj) on rearrangement with sulfuric acid yielded the corresponding amines IVe, IVf, IVi, and IVj. In spite of the slow rate of rearrangement of these N-oxides, attempts to isolate the intermediate hydroxyaminospirolactams (III) were unsuccessful.
SYNTHESIS OF THE TRIMETHOXYPHENYLPROPENES
Authors: Shulgin Alexander T.
Published: May 2006

not available
THE USE OF DIMETHYLFORMAMIDE AND OF DIMETHYL SULFOXIDE IN THE PREPARATION OF 2,4-DINITROPHENYLHYDRAZONES
Authors: Parrick J. , Rasburn J. W.
Published: May 2006

not available
THE REACTION OF SOME TITANIUM AND ZIRCONIUM HALIDES WITH CYCLIC ORGANIC LIGANDS CONTAINING OXYGEN AND SULFUR
Authors: Alyea E. C. , Torrible E. G.
Published: May 2006

not available
RARE-EARTH ACETATE ION ASSOCIATION
Authors: Manning P. G.
Published: May 2006

not available
CKM PARAMETERS AND RARE B DECAYS
Authors: FORTI FRANCESCO
Published: May 2006

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the loop diagrams. In this paper the recent measurements performed in this area by BABAR and Belle will be presented. The direct measurement of the angle α is for the first time as precise as the indirect determination. The precision of the |Vub| determination has improved significantly with respect to previous measurement. New limits on B → τν decays are presented, as well as updated measurements on b → s radiative transitions and a new observation of b → dγ transition made by Belle.
Liver-Specific Inhibition of Acyl-Coenzyme A:Cholesterol Acyltransferase 2 With Antisense Oligonucleotides Limits Atherosclerosis Development in Apolipoprotein B100–Only Low-Density Lipoprotein Receptor
−/−
Mice
Authors: Bell Thomas A. , Brown J. Mark , Graham Mark J. , Lemonidis Kristina M. , Crooke Rosanne M. , Rudel Lawrence L.
Published: May 2006

Objective—

The purpose of this study was to determine the effects of liver-specific inhibition of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2) on the development of hypercholesterolemia and atherosclerosis in mice.

Methods and Results—

Apolipoprotein B100–only low-density lipoprotein (LDL) receptor
−/−
mice were given saline, a nontargeting control antisense oligonucleotide (ASO), or ASOs targeting ACAT2 biweekly for a period spanning 16 weeks. Mice treated with ACAT2 targeting ASOs had liver-specific reduction in ACAT2 mRNA, yet intestinal ACAT2 and cholesterol absorption was left undisturbed. ASO-mediated knockdown of ACAT2 resulted in reduction of total plasma cholesterol, increased levels of plasma triglyceride, and a shift in LDL cholesteryl ester (CE) fatty acid composition from mainly saturated and monounsaturated to polyunsaturated fatty acid enrichment. Furthermore, the liver-specific depletion of ACAT2 resulted in protection against diet-induced hypercholesterolemia and aortic CE deposition. This is the first demonstration that specific pharmacological inhibition of ACAT2, without affecting ACAT1, is atheroprotective.

Conclusions—

Hepatic ACAT2 plays a critical role in driving the production of atherogenic lipoproteins, and therapeutic interventions, such as the ACAT2-specific ASOs used here, which reduce acyltransferase 2 (ACAT2) function in the liver without affecting ACAT1, may provide clinical benefit for cardiovascular disease prevention.