bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereospecific and Stereoselective Reactions. II. Preparation of Esters of N-Phthaloyl-α-amino Acid from Esters of α-Hydroxy Acid
Authors: Wada Makoto , Sano Takashi , Mitsunobu Oyo 
Published: July 2006

Abstract
Functional selectivity and stereospecificity of the intermolecular dehydration between alcohols and phthalimide (III) by means of diethyl azodicarboxylate (I) and triphenylphosphine (II) was examined. The reaction of allyl alcohol, 2-chloroethanol or (±)-ethyl lactate with I, II, and III led to the formation of corresponding N-alkylphthalimide. The reaction was further applied to the synthesis of esters of N-phthaloyl-α-amino acid. (S)-(−)-ethyl 2-hydroxy-3-phenylpropionate was converted into (R)-(+)-N-phthaloylphenylalanine ethyl ester with high stereospecificity.
New Furanoeremophilane Derivatives from Farfugium japonicum Kitamura
Authors: Nagano Hajime , Tanahashi Yoshiaki , Moriyama Yoshihiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
Five new furanoeremophilane derivatives, I, II, III, IV, and V, have been isolated from Farfugium japonicum Kitamura, and their structures have been determined. Conformations of some furanoeremophilane derivatives are discussed.
Transylidations of Stable Sulfonium Ylids
Authors: Matsuyama Haruo , Minato Hiroshi , Kobayashi Michio 
Published: July 2006

Abstract
In the presence of a dialkoxy disulfide, sulfonium bis(methoxycarbonyl)methylids underwent transylidation with a dialkyl sulfide or pyridine at 35 °C. Thiocyanogen and benzoyl disulfide showed a similar catalytic effect. The kinetics of this reaction were investigated, and its mechanism was discussed.
Thermodynamic Properties of Moderately-concentrated Poly (γ-benzyl-l-glutamate) Solutions
Authors: Okamoto Akio , Kubo Kenji , Ogino Kazuyoshi 
Published: July 2006

Abstract
The osmotic pressures for poly(γ-benzyl-l-glutamate) solutions in ethylene dichloride and chloroform were measured at 29 °C in the concentration range of 2–15 vol % polymer. The osmotic pressures increased monotonously with an increase in the concentration. No evidence was found for the coexistence of two phases. The results are compared with the theory of the solutions of rodlike molecules. The values of the thermodynamic interaction parameter, χ, for the systems were found to be 0.44–0.47 in the concentration range lower than 6.5 vol% polymer, where the solutions must be isotropic.
Radiation Chemical Studies with Cyclotron Beams. III. The Heavy-ion Radiolysis of Liquid Aliphatic Ketones
Authors: Matsui Masao , Imamura Masashi 
Published: July 2006

Abstract
The liquid-phase radiolysis of acetone, methyl ethyl ketone, and diethyl ketone with 4He–, 12C–, and 14N–ions was carried out with the intention of discovering the specific reactions taking place in a very high LET region. The heavy ions were accelerated at various energies with an IPCR cyclotron, the LET of which was up to 80 eV/Å. The radiolytic yields of the main gaseous products, hydrogen and carbon monoxide, were found to increase appreciably with an increase in the LET and to reach the maximum values in the LET region between 50 and 70 eV/Å. The ratios of the two yields, G(H2)/G(CO), also increase substantially with an increase in the LET. These results, as well as the variations in the yields of saturated and unsaturated hydrocarbons, appear to indicate a thermal-spike effect which may bring about the thermal decomposition of free radicals, giving rise to the enhanced G(H2) and G(CO) values in the high LET region.
Temperature Dependence of the Lattice Vibrations of Triglycine Sulfate
Authors: Kaneko Norio , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
Far infrared spectra from 400 to 30 cm−1 of triglycine sulfate and its deuterated analogue were measured and the bands due to the librational modes of glycine molecules were identified. Polarized Raman spectra below 300 cm−1 of triglycine sulfate single crystals were measured and the symmetry species of the observed lattice vibrations were determined. Temperature dependence of the lattice vibrations was examined. Significant changes were detected in both infrared and Raman spectra on crossing the Curie temperature, indicating a flipping motion of glycine I in the paraelectric phase and suggesting the ferroelectric transition in triglycine sulfate to be of an order-disorder type.
Interactions of β-Naphthol and β-NaphthyIamine in Their Excited Singlet States with Triethylamine
Authors: Matsuzaki Akiyoshi , Nagakura Saburo , Yoshihara Keitaro 
Published: July 2006

Abstract
Proton donor-acceptor interactions in excited states were studied by measuring mainly time-resolved fluorescence spectra for β-naphthol–TEA in toluene and in acetonitrile, and for β-naphthylamine–TEA in nonpolar mixed solvents. The Stern-Volmer relation was found to be satisfied for β-naphthol–TEA in toluene. The rate constant and activation energy of hydrogen bond formation in the excited state of this system were obtained to be 2.2×109 M−1 s−1 at 30 °C and 1.6 kcal/mol, respectively, indicating that the process is diffusion-controlled. The time dependences of the intensities of the fluorescence bands due to the free and complexed β-naphthol were measured with the solutions containing various concentrations of triethylamine in acetonitrile. From the analysis of the result, it is shown that this system is led to the ion-pair formation via the hydrogen-bonded species in the excited state. For β-naphthylamine–TEA in nonpolar mixed solvents, the bands due to hydrogen-bonded species in the ground and excited states were observed at 370 and ∼390 nm in the absorption and fluorescence spectra, respectively.
Dehydrogenation of 2-(1-Cyclohexenyl)cyclohexanone with Palladium Catalyst
Authors: Imafuku Kimiaki , Oda Junko , Itoh Kenshi , Matsumura Hisashi 
Published: July 2006

Abstract
The dehydrogenation reaction of 2-(1-cyclohexenyl)cyclohexanone was carried out in the presence of 5% palladium-on-charcoal at temperatures 280, 300, and 320 °C, the reaction time being 1/2—8 hr. o-Cyclohexylphenol and o-phenylphenol were obtained as dehydrogenation products, and dibenzofuran as the cyclization product via o-phenylphenol. In a short reaction time, 2-cyclohexylcyclohexanone was formed together with the dehydrogenation products. The compound disappeared, the amount of two phenols and dibenzofuran increasing with reaction time. The dehydrogenation process is discussed.
Regio- and Stereo-selectivities in the Epoxidations of Limonene, endo-Dicyclopentadiene, and exo-Dicyclopentadiene
Authors: Sato Tadashi , Murayama Eigoro 
Published: July 2006

Abstract
The regio- and stereo-selectivities were observed in the radical and peracid epoxidations of limonene, endo-, and exo-dicyclopentadienes. The observations were considered in view of the proposed mechanisms for these reactions.
The Photo-Fries Rearrangement of Aryloxy-1,3,5-triazines
Authors: Ohto Yukio , Shizuka Haruo , Sekiguchi Shizen , Matsui Kohji 
Published: July 2006

Abstract
Aryloxy-s-triazines gave o- and/or p-hydroxyaryl-s-triazines upon irradiation; however, from arylamino-and arylthio-s-triazines, no photo-rearrangement product was obtained. The p-CH3, p-Cl, and p-OCH3 groups in the phenoxy moiety did not prevent the photoreaction of aryloxy-s-triazines; however, the p-CHO, p-COCH3, p-COOC2H5, and p-NO2 groups prevented the photoreaction. As to substituents in the s-triazine moiety, such groups as –Cl, –OCH3, –OC6H5, and –CH3 did not prevent the photoreaction; however, C6H5 and amino groups prevented the reaction. In the photolysis of 2,4-dimethoxy-6-(1-naphthyloxy)-s-triazine, 1-hydroxy-2-naphthyl- and 4-hydroxy-1-naphthyl-s-triazines were obtained, with the preferential formation of the former. On the other hand, from 2,4-dimethoxy-6-(2-naphthyloxy)-s-triazine, 2-hydroxy-1-naphthyl-s-triazine was obtained upon irradiation. In a similar manner, 2- and 4-acetyl-1-naphthols were obtained from 1-naphthyl acetate, and 1-acetyl-2-naphthol was isolated from 2-naphthyl acetate.
Addition of Methanesulfenyl Chloride and Sulfur Chloride to 1,4-Dimethyl-3,6-dimethylene-2,5-piperazinedione and Substitution of the Adducts
Authors: Yoshimura Juji , Sugiyama Yuichi , Matsunari Kenji , Nakamura Hiroshi 
Published: July 2006

Abstract
Addition of methanesulfenyl chloride or sulfur chloride to 3,6-dimethylene-(1a) and 3,6-dibenzylidene-1,4-dimethyl-2,5-piperazinediones (1b) gave the Markownikoff products. The addition of methanesulfenyl chloride to 1a proceeded stepwise within 1 hr, and gave a mixture of (Z,Z)-, (Z,E)-, and (E,E)-isomers of the corresponding 3,6-bis(methylthiomethylene) derivative, accompanied by gradual elimination of hydrogen chloride. 3,6-Di-chloro groups of the adduct were substituted with water, ethanethiol and ethanol to give the corresponding hydroxy, ethylthio, and ethoxy derivatives, respectively. A similar substitution with ethanedithiol and hydrogen sulfide followed by aeration gave 7,9-dimethyl-1,6-bis(methylthiomethyl)-8,10-dioxo-2,5-dithia-7,9-diazabicyclo[4,2,2]-decane and the corresponding 3,6-epitetrathio derivative, respectively. The same mode of reaction of sulfur chloride with 1a and 1b gave a few 1,6-disubstituted-7,9-dimethyl-8,10-dioxo-3,4-dithia-7,9-diazabicyclo[4,2,2]-decanes. Mass fragmentations of new compounds were also described.
Solvent Effects in Diazo-coupling Reactions
Authors: Hashida Y\={o}ji , Ishida Hiroki , Sekiguchi Shizen , Matsui Kohji 
Published: July 2006

Abstract
The kinetics of the diazo-coupling reactions of benzenediazonium fluoroborates with 1,3,5-trimethoxybenzene and 2-naphthol have been studied in non-aqueous media including both protic and dipolar aprotic solvents. In the case of the reaction with 1,3,5-trimethoxybenzene, no significant solvent effect on the reaction rate was observed. However, in the case of the reaction with 2-naphthol, the reaction rate was affected markedly by the solvent; in dipolar aprotic solvents, the reaction proceeded much faster than in protic solvents. The observed results are interpreted in terms of the difference in solvation toward the naphtholate ion.
Solution Properties of Phycocyanin. I. Studies of Dissociation-Association by Sedimentation Measurement
Authors: Saito Takahide , Iso Naomichi , Mizuno Haruo 
Published: July 2006

Abstract
The dissociation-association properties of phycocyanin, isolated from the red algae, “Porphyra tenera,” have been investigated by sedimentation velocity measurements at pH 6.8 and 5.4 and at the ionic strengths of 0.1 and 0.2. The sedimentation coefficient data indicated that the predominant component in the phycocyanin solution was a trimer at pH 6.8 and a hexamer at pH 5.4. The concentration dependence of the sedimentation coefficient for various hypothetic systems of the dissociation-association equilibrium of phycocyanin was simulated by a computer model. It was reasonable to consider, from the simulation, that the dissociation-association system of phycocyanin was trimer\ightleftharpoonsmonomer at pH 6.8 and hexamer\ightleftharpoonsmonomer at pH 5.4. The dissociation constant was calculated for each system. The value of the dissociation constant was 0.15×10−4 (g/dl)2 at pH 6.8 and an ionic strength of 0.1; 0.13×10−4 (g/dl)2 at pH 6.8 and an ionic strength of 0.2; 0.5×10−13 (g/dl)5 at pH 5.4 and an ionic strength of 0.1 and 0.1×10−13 (g/dl)5 at pH 5.4 and an ionic strength of 0.2. The dissociation constants decrease with an increase in the ionic strength in solution.
Three Methods to Look at Walsh-type Diagrams Including Nuclear Repulsions
Authors: Takahata Yuuzi , Parr Robert G 
Published: July 2006

Abstract
Energy correlation diagrams for molecules of type AH2 are examined by three different methods: (1) the quantum-mechanical virial theorem, (2) the method of median partition, (3) the integral Hellmann-Feynman theorem. Nuclear-nuclear repulsions are included. The formula for the first method takes the form W=−Σti, where ti is an orbital kinetic energy. The theory is applied to H2O, CH2, and BeH2. Negative-kinetic-energies-versus-angle diagrams for these molecules are presented. The pattern of the diagrams is quite different from the usual Walsh diagram. With this resolution non-bonding electrons play a significant role in determining bond angles. In the second method the resolution of the total energy takes the form W=Σi[ei+Vn(i)], where ei is a median electronic energy and Vn(i) is a resolved nuclear repulsion energy calculated from an expression derived from ideas of population analysis. The energies-versus-angle diagram thus obtained for H2O is similar to the one obtained by the first method. For the third method, the integral Hellmann-Feynman formula for the electronic energy change on bending is written in terms of corresponding orbital contributions, ΔEl=ΣiΔEl(i), and nuclear-nuclear repulsion is added in a resolved form. For H2O the ΔEl resemble Walsh diagrams closely, both with and without the nuclear-nuclear repulsion increments. Wave functions used throughout are LCAO-SCF functions built from medium-size Gaussian basis sets.
On the EPR Emission Spectrum of Transient Naphthosemiquinone Radical
Authors: Yoshida Hiroshi , Sohma Junkichi , Warashina Tetsuo 
Published: July 2006

Abstract
EPR spectrum in emission mode at the low-field hyperfine lines was observed for 1,4-naphthosemiquinone radical formed by the steady-state photolysis of solution of corresponding quinone in ethanol flowing through the cavity. Observed behavior of this spectrum was analyzed by a phenomenological way. The results support the view that the anomalous electron spin polarization is generated in the radical formation process. The conclusion was compared with the results of intermittent photolysis.
Topochemical Studies. III. The Crystal and Molecular Structures of Crotonic Acid, CH3CH=CHCOOH, and Crotonamide, CH3CH=CHCONH2
Authors: Shimizu Shozo , Kekka Shinji , Kashino Setsuo , Haisa Masao 
Published: July 2006

Abstract
Crotonic acid crystallizes in the monoclinic space group C2/c, with a=15.30(3), b=4.06(1), c=16.18(2) Å, β=107.4(1)° and Z=8; crotonamide in the monoclinic space group P21/a, with a=9.71(2), b=6.90(2), c=7.75(1) Å, β=104.0(4)° and Z=4. The structures have been solved by the Patterson method and refined by the block-diagonal least-squares method. The final R values are 0.090 for 337 observed reflections for crotonic acid, and 0.088 for 525 observed ones for crotonamide. The configuration of the molecules of crotonic acid and crotonamide is approximately planar and of trans-type regarding the C=C bond. Every two centrosymmetrically related molecules form a dimer through hydrogen bonds of 2.645 Å (OH···O) for crotonic acid and 2.963 Å (NH···O) for crotonamide. In the crystals of crotonamide additional NH···O hydrogen bonds (2.862 Å) link the neighboring molecules related by the a-glide plane to form a sheet parallel to (001) plane. Distances between the C=C bonds of the nearest neighbors are 3.86 Å for crotonic acid and 3.62 and 3.88 Å for crotonamide.
Polarographic and Anodic Stripping Polarographic Studies of Aliphatic Polyamine Complexes of Several Metal Ions
Authors: Komatsu Masahiro 
Published: July 2006

Abstract
The polarography of several aliphatic polyamine complexes of Pb(II), Zn(II), and Ni(II), and the anodic stripping polarography of polyamine complexes of Zn(II), Cd(II), Pb(II), and Cu(II) were studied. The aliphatic polyamines used were ethylenediamine(en), 1,3-propanediamine(1,3-pn), 1,2-propanediamine(1,2-pn), diethylenetriamine(den), and triethylenetetramine(trien). These lead(II) complexes gave a one-step reversible wave which was diffusion-controlled. The relation between the logarithm of the concentration of polyamine and the halfwave potential of the Pb(II) complex was straight, so that one species of complex ion was found to be predominant in the bulk of solution. The ionic species in the bulk of solution were found to be Pb(en)22+, Pb(1,3-pn)22+, Pb(1,2-pn)22+, Pb(den)22+, and Pb(trien)2+. The stability constants of these complexes were calculated and were found to increase in the order of Pb(1,3-pn)22+&lt;Pb(en)22+&lt;Pb(1,2-pn)22+&lt;Pb(den)22+&lt;Pb(trien)2+. The polarographic waves of Zn(II)-polyamine and Ni(II)-polyamine complexes were irreversible and diffusion-controlled, so the electrode reactions of these complexes were assumed using Matsuda-Ayabe’s theory. All these polyamine complexes of Zn(II), Cd(II), Pb(II), and Cu(II) gave well-defined anodic stripping polarograms. 1,3-pn was the best complexing reagent among these polyamines, because it gave the best separation of the peaks of the anodic stripping polarograms of the four metal ions. Calibration curves were obtained from 0.01 to 0.10 ppm for Zn(II), Pb(II), and Cu(II), and from 0.001 to 0.010 ppm for Cd(II) in 0.4 M 1,3-pn and 0.2 M KCl media. The effects of acid and base on the anodic stripping polarograms were also studied.
The Complexing of the Sodium Ion in Acetonitrile with Other Solvents. Investigation by the Use of a Cationsensitive Glass Electrode
Authors: Izutsu Kosuke , Nomura Toshiaki , Nakamura Toshio , Kazama Hidetoshi , Nakajima Shigeo 
Published: July 2006

Abstract
The complexing of the sodium ion in acetonitrile (AN) with such solvents as methanol, water, DMF, DMA, DMSO, HMPA, and pyridine has been studied potentiometrically by using a monovalent cation-sensitive glass electrode. The reference electrode of Ag-0.005 M AgNO3(AN) and the salt bridge of 0.1 M Et4NPi(AN) were used. Mono- and di-solvated ions were formed for methanol, water, and pyridine. For DMF, DMA, DMSO, and HMPA, tri-solvated species were also formed. The formation constants for the mono-solvated sodium ion were 0.7 for pyridine, 1 for methanol, 1.8 for water, 2.5 for DMF, 5 for DMA, 6 for DMSO, and 30 for HMPA.
Effect of Ethanol on the Outer-sphere Association of Λ- or Δ-Tris(ethylenediamine)cobalt(III) with d-Tartrate Ions in Aqueous Solutions
Authors: Yoneda Hayami , Miyoshi Katsuhiko , Suzuki Shingo , Taura Toshiaki 
Published: July 2006

Abstract
The effect of ethanol on the outer-sphere association of Λ- or Δ-[Coen3]3+ ion (en=ethylenediamine) with d-tartrate ion was investigated in aqueous solutions containing 0,1,3, and 5 wt% of ethanol at 25 °C by measuring the change in optical density of the charge-transfer spectra at 265 nm. It was found that the association constant of Λ-[Coen3]3+ ion with d-tartrate ion KA(Λ) was a little larger than that of Δ-[Coen3]3+ ion KA(Δ), and that the addition of ethanol increased both KA(Λ) and KA(Δ) but decreased the ratio KA(Λ)⁄KA(Δ). The diminished discrimination between Λ- and Δ-[Coen3]3+ ions by d-tartrate ion was discussed in terms of the solubility of these diastereoisomers in aqueous ethanol and was attributed to the increased electrostatic interaction between the complex and d-tartrate ions arising from the decrease in the dielectric constant of the medium.
Potentiometric and Spectrophotometric Studies of Fluoride Complexes of Uranium(IV)
Authors: Kakihana Hidetake , Ishiguro Shin-ichi 
Published: July 2006

Abstract
The stability constants and the molar extinction coefficients of uranium(IV) fluoride complexes were determined in aqueous solutions containing 1 M (Na++H+)Cl− as a constant ionic medium at 25 °C. The emf data obtained by the use of a fluoride-ion-selective electrode were explained in terms of the formation of a series of mononuclear complexes, UF3+, UF22+, UF3+, and UF4, with stability constants β1=(2.2±0.13)×107, β2=(1.33±0.05)×1013, β3=(2.9±0.5)×1017, and β4=(6±1)×1021 respectively. Using these values for β’s the spectra observed in the 350–700 nm region were analyzed by means of a computer in order to estimate the molar extinction coefficients of each uranium(IV) fluoride complex species.
Carbonylation of Alcohols, Olefins, and Saturated Hydrocarbons by CO in the Ag(I)–H2SO4 System
Authors: Souma Yoshie , Sano Hiroshi 
Published: July 2006

Abstract
In the presence of an Ag carbonyl-ion catalyst, prepared in situ from the Ag compound and carbon monoxide in H2SO4, olefins or alcohols reacted with carbon monoxide at room temperature and atmospheric pressure to produce exclusively tertiary carboxylic acids in high yields. The amount of Ag compound sufficient for carrying out the reaction is ca. 0.2 mol/l. The optimum reaction temperature is 0–40°C. The reaction proceeds practically at above a 90% H2SO4 concentration. Saturated hydrocarbons, containing a tertiary hydrogen, also reacted with carbon monoxide in the presence of alcohols or olefins as carbonium ion precursors, thus producing tertiary carboxylic acids.
The Reaction of 3-(ω-EthoxycarbonyIacetyl)-2H-cyclohepta[b]furan-2-one with Active Methylene Compounds
Authors: Nozoe Tetsuo , Takase Kahei , Nakazawa Tomoo , Sugita Satoko , Saito Motoyasu 
Published: July 2006

Abstract
The reaction of 3-(ω-ethoxycarbonylacetyl)-2H-cyclohepta[b]furan-2-one (4) with malononitrile and with cyanoacetamide, in the presence of sodium ethoxide, gave 4-hydroxyazuleno[2,1-b]pyrid-2(1H)-one derivatives, (5) and (9) respectively, in good yields. On the other hand, the reaction of 4 with ethyl cyanoacetate gave 3-cyano2-ethoxycarbonylmethylazulene-1-carboxylic acid (12). The structures of these products were determined on the basis of the spectral data and some chemical evidences.
New Photochemical Reactions of 9-ω-Bromoacetylanthracene. I
Authors: Matsumoto Tamotsu , Sato Masanori , Hirayama Satoshi 
Published: July 2006

Abstract
New photochemical reactions were found on 9-ω-bromoacetylanthracene. The main photo-products were 1-aceanthrenone and 9-bromoanthracene. Their formation was not appreciably affected by the presence of oxygen. Other products such as anthracene, 9-acetylanthracene and anthraquinone were also detected and their yields greatly depended on the reaction conditions. From the low temperature experiments, it was made clear that 9-bromoanthracene and 1-aceanthrenone were formed via different mechanisms. A rather stable intermediate, which was not a radical but presumably an intramolecular adduct, was detected spectroscopically. 1-Aceanthrenone was formed from the intermediate both photochemically and thermally with liberation of hydrogen bromide. In the absence of oxygen both the thermal and photochemical reactions of the intermediate yielded almost the same amount of 1-aceanthrenone. The reaction mechanisms were considered in reference to the photochemical reactions of 9-nitroanthracene and sodium 9-anthroate. The relation between these reactions and the radiationless transition processes of carbonyl derivatives of anthracene was also discussed.
Phase Diagrams of YCl3–KCl, YCl3–NaCl, and YCl3–KCl·NaCl Systems, and Densities of Their Molten Mixtures
Authors: Mochinaga Junichi , Irisawa Kyozan 
Published: July 2006

Abstract
YCl3 has been prepared with Y2O3 and NH4Cl, and the optimum conditions for chlorination have been determined. The YCl3 salt obtained was purified to a pure YCl3 crystal by sublimation. Pnase diagrams of binary YCl3–KCl and YCl3–NaCl system, and liquidus curve diagram of quasi-binary YCl3–KCl·NaCl system have been determined with the use of the purified YCl3 crystal. Densities of YCl3 and the mixtures in molten state were measured dilatometrically, and represented by empirical formulas as a function of temperature. From the results thermal expansion coefficients and molar expansibilities of the molten YCl3 and the molar volumes of molten mixtures were calculated.