bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immobilization of β-Cyclodextrin on Silica Gel
Authors: Shiraishi Shinsaku , Komiyama Makoto , Hirai Hidefumi 
Published: July 2006

Abstract
β-Cyclodextrin (β-CyD) was covalently immobilized on silica gel by chlorination of silica gel with thionyl chloride or silicon tetrachloride, followed by the reaction of the resulting chlorinated silica gel with β-CyD in pyridine. The amounts of the immobilized β-CyD were 8×10−5 to 1.4×10−4 mol per 1 g of the β-CyD–silica gel composites. On heating, the composites did not exhibit weight decrease up to 250 °C. The β-CyD in the composites formed 1 : 1 complex with phenol in aqueous solutions, and the equilibrium constant for the dissociation of the complex was 6×10−3 mol dm−3 at 25 °C. The immobilized β-CyD exhibited catalytic activity in the cleavage of 4-nitrophenyl acetate at 25 °C, pH 8.7.
Stereoselective Preparation of Acyclic syn-β-Amino Alcohols from β-Hydroxy Ketones via the Corresponding O-Benzyl Oximes
Authors: Narasaka Koichi , Ukaji Yutaka , Yamazaki Shigeru 
Published: July 2006

Abstract
Reduction of β-hydroxy ketone O-benzyl oximes with lithium aluminum hydride in the presence of sodium or potassium methoxide afforded the corresponding syn-β-amino alcohols in highly stereoselective manner. A lythraceae alkaloid, lasubine II, was synthesized stereoselectively by applying this method.
Sulfur K-Edge Absorption Spectra of Na2SO4, Na2SO3, Na2S2O3, and Na2S2Ox (x=5–8)
Authors: Sekiyama Hideo , Kosugi Nobuhiro , Kuroda Haruo , Ohta Toshiaki 
Published: July 2006

Abstract
X-Ray absorption spectra of the sulfur K-edges of SO42−, SO32−, S2O32−, and S2Ox2− (x=5–8) were measured with synchrotron radiation. The spectra show similarly strong absorption bands which originate in bound-state transitions to antibonding 3p-type orbitals and in shape resonances related to 3d-type orbitals. The K-edge spectrum for the terminal sulfur atom in S2O32−, however, shows only a bound-state transition. Differences in chemical environments and bonding around the X-ray absorbing atoms are discussed to interpret the spectra.
Solvent Effect on the Liquid–Liquid Partition Coefficients of Dimethyldithiocarbamic Acid and Its Copper(II) Chelate
Authors: Imura Hisanori , Matsumora Satoru , Suzuki Nobuo 
Published: July 2006

Abstract
Partition coefficients of dimethyldithiocarbamic acid and its copper(II) chelate have been determined in various organic solvents −0.10 mol dm−3 aqueous perchlorate solution systems at 25 °C. The effects of inert organic solvents are explained with the aid of the regular solution theory. Also, a linear free-energy relationship between the partition coefficient of the copper(II) chelate and that of the reagent is demonstrated. The partition coefficient of the copper(II) chelate is compared with that of bis(2,4-pentanedionato)copper(II) and various factors governing the partition coefficients of these chelates are discussed with the aid of the scaled particle theory.
Amijitrienol and 14-Deoxyisoamijiol, Two New Diterpenoids from the Brown Seaweed Dictyota linearis
Authors: Ochi Masamitsu , Asao Kazuhiko , Kotsuki Hiyoshizo , Miura Iwao , Shibata Kozo 
Published: July 2006

Abstract
The structures of amijitrienol and 14-deoxyisoamijiol, two new diterpenoids isolated from the brown seaweed Dictyota linearis, have been established as 1 and 2 on the basis of spectral and chemical evidence.
An Improved Synthesis of N-Trifluoroacetyl-l-daunosamine
Authors: Kimura Yoshikazu , Matsumoto Teruyo , Suzuki Michiyo , Terashima Shiro 
Published: July 2006

Abstract
A process which can afford a large quantity of the title compound was explored by modifying the Horton’s original route. The developed process features highly stereoselective reduction of the oxime with sodium dihydrobis(2-methoxyethanolato)aluminate(1-) and efficient dehydrobromination with 1,8-diazabicyclo[5.4.0]undec-7-ene.
Reactions of Sodium Hydrogentelluride with α-Azido Ketones and α-Azido Bromides
Authors: Suzuki Hitomi , Kawaguchi Takashi , Takaoka Koji 
Published: July 2006

Abstract
When treated with sodium hydrogentelluride in ethanol at room temperature, α-azido ketones are easily converted to pyrazines via the self-condensation of initially formed α-amino ketones followed by aerobic oxidation during work-up. On a similar treatment, activated α-azido bromide such as 1,2-diphenyl-1-azido-2-bromoethane suffers E2-type β-elimination to give the corresponding olefin as the sole product, while ordinary α-azido bromides afford complicated mixtures containing amino and olefinic compounds among other products.
Isopropylidenation of Raffinose
Authors: Otake Toshiki , Tsukahara Junko 
Published: July 2006

Abstract
A reaction of raffinose with an excess amount of 2,2-dimethoxypropane and p-toluenesulfonic acid as a catalyst in N,N′-dimethylformamide, followed by acetylation, gave seven kinds of mono-, di, or tri-O-isopropylideneraffinose peracetates with at least five kinds of minor products. A reaction of raffinose with a limited amount of 2,2-dimethoxypropane gave a new isopropylidene derivative with some of the derivatives described above. The isopropylidenation occurred at 1′,2-, 2,3-, 2″,3″-, 3,4-, 3″,4″-, and 4″,6″-positions. The structures of these compounds were established by 1H and 13C NMR analyses.
The Electrical Properties of La2−xSrxNiO4 (0≤x≤1)
Authors: Ishikawa Kenji , Kondo Shin-ichi , Suzuki Yuichi , Takayama Shin-ichi , Shimada Kazuhiko , Suzuki Yasuo 
Published: July 2006

Abstract
The electrical resistivities and Seebeck coefficients of mixed oxides, La2−xSrxNiO4, have been determined under an He atmosphere at 77.4–673.2 K. It has been shown that the temperature dependences of the Seebeck coefficients of the oxides were fairly well approximated by this equation: S=AT+B+C⁄T, where T is the thermodynamic temperature. The coefficients of the equation, A, B, and C, were given by the least-squares method. The metal-semiconductor ratios {α≡(C⁄T)⁄(AT+C⁄T)} were given to characterize the thermoelectrical properties of La2−xSrxNiO4. The maximal activation energies (Ea(resis.) and Ea(Seebeck)) and the maximal metal-semiconductor ratio (α) were obtained with the strontium concentration of La2−xSrxNiO4 at x=0.5. The lattice distortion of the oxides is responsible for the maxima of the activation energies and of the metal-semiconductor ratio at x=0.5.
Spectrophotometric Determination of Micro Amounts of Thiocyanate via Permanganate Reaction
Authors: Miura Yasuyuki , Koh Tomozo 
Published: July 2006

Abstract
A method has been developed for the determination of micro amounts of thiocyanate. It is based on the reaction of thiocyanate with a given amount of permanganate as an oxidizing agent in a dilute sulfuric acid medium and on the spectrophotometric measurement of iodine as triiodide, which is formed by the oxidation of iodide with an excess of permanganate for its reaction with thiocyanate. The conditions for the thiocyanate to be quantitatively oxidized were established by varying the temperature, reaction time, and amounts of sulfuric acid and permanganate. The present method can be successfully applied to the determination of thiocyanate in the range from 7×10−7 to 4×10−5 mol dm−3 (0.4–23.2 μg SCN− in 10 cm3). In eleven determinations for 10-cm3 sample solutions containing 0.250 μmol of thiocyanate, the present method gave a mean value of 0.251 μmol, with a standard deviation of 0.0022 μmol and a relative standard deviation of 0.88%. Chloride, bromide, iodide, and cyanide did not interfere with the determination of 14.5 μg of thiocyanate in the presence of 1000 μg, 500 μg, 100 μg and 50 μg, respectively.
Oxidation of Alcohols and Ethers Using Sodium Bromate–Hydrobromic Acid System
Authors: Kajigaeshi Shoji , Nakagawa Takashi , Nagasaki Noritaka , Yamasaki Hiromichi , Fujisaki Shizuo 
Published: July 2006

Abstract
Reaction of primary alcohols or simple ethers, α,ω-diols or cyclic ethers, and secondary alcohols with sodium bromate in the presence of catalytic amount of hydrobromic acid under mild conditions gave dimeric esters, lactones, and ketones in fairly good yields, respectively.
Hydration of the Oxyethylene Chain. Hypersonic Velocities in Aqueous Solutions of α-Methyl-ω-methoxyoligo(oxyethylene)s and α-Methyl-ω-hydroxyoligo(oxyethylene)s as Studied by Brillouin Scattering
Authors: Matsuura Hiroatsu , Fukuhara Koichi 
Published: July 2006

Abstract
Hydration of the oxyethylene chain was studied by a Brillouin-scattering method; hypersonic velocities in aqueous solutions of CH3(OCH2CH2)mOCH3 with m=1–4 and CH3(OCH2CH2)mOH with m=2 and 3 were measured. The concentration of the solution, at which the sound velocity gave a maximum value, led to the number of water molecules, at the highest hydration, per ether linkage in the oxyethylene chain. The experimental results showed that 1.8 water molecules take part in the hydration of each –CH2OCH2– group and that the number of the water molecules is virtually constant independently of the oxyethylene-chain length as far as the number of the oxyethylene units is limited up to four. These findings indicate that a sort of hydration complex of approximately 1 –OCH2CH2–:2 H2O is formed in the aqueous solution. It is suggested that the stabilization of the gauche conformation for the OCH2–CH2O group in aqueous solution, as evidenced by Raman-spectroscopic observations, is promoted greatly by the hydrogen bond of water molecules which are bridged between the adjacent ether oxygens in the oxyethylene chain.
The Hydrogenation of Benzil Catalyzed by Cobalt(II) Dimethylglyoxime Complex
Authors: Mita Keisuke 
Published: July 2006

Abstract
Kinetic studies on the catalytic hydrogenation of benzil to benzoin by bis(dimethylglyoximato)cobalt(II), Co(Hdmg)2, were carried out by varying the concentration of Co(Hdmg)2 and pyridine. The initial rate of the hydrogenation reaction was first order with respect to the overall cobalt concentration at a constant overall pyridine concentration. On the other hand, the rate passed through a peak as the overall pyridine concentration was increased at a constant overall cobalt concentration. The peak was observed at [py]T=130 mmol dm−3, where the square bracket denotes the concentration in the liquid phase. These results show that the initial reaction rate, Vin, can be expressed by the following rate equation,
V in=k[Co(Hdmg)2]\frac58[py]T1+58[py]T,
where, k=1.1 min−1.
Hydrates of Organic Compounds. X. The Formation of Clathrate Hydrates of Tetrabutylammonium Alkanesulfonates
Authors: Nakayama Haruo , Usui Hideyuki 
Published: July 2006

Abstract
The solid–liquid phase diagrams of binary mixtures of water with tetrabutylammonium alkanesulfonate (n-C4H9)4NO3SR(R=CH3–C5H11) and with tetrabutylammonium benzenesulfonate were examined in order to confirm the formation of clathrate-like hydrates. It has been found that (1) all the sulfonates examined can form clathrate-like hydrates with hydration numbers either around 30 or around 39; (2) these hydrates can be classified into three groups I, II, and III on the basis of the hydration numbers and melting points just as in the case of a series of tetrabutylammonium carboxylate hydrates; and (3) generally, the melting points of these sulfonate hydrates are lower than those of tetrabutylammonium carboxylate hydrates. The formation of clathrate-like hydrates of tetrabutylammonium hydrogensulfite and of tetrabutylammonium sulfite has also been reported and is discussed in an appendix.
Absorption Spectra of Tetrahedral Co(II) in Single Crystals of [N(CH3)4]2[CoX4] (X=Cl,Br)
Authors: Kojima Kazuo , Matsuda Jiro 
Published: July 2006

Abstract
The optical absorption spectra of single crystals of [N(CH3)4]2[CoCl4] and [N(CH3)4]2[CoBr4] have been measured over the range of 4000–33000 cm−1 at the temperature of liquid nitrogen and at room temperature. The spectra have been analyzed using the crystal-field theory which includes spin-orbit coupling. Some discussion of the Racah parameter B and of the 4T1(4F) and 4T1(4P) states is presented.
The Separation and Concentration of Gallium(III) and/or Indium(III) Using Polystyrene Resins Functionalized with Complexane-Type Ligands
Authors: Suzuki Toshishige M , Yokoyama Toshiro , Matsunaga Hideyuki , Kimura Tetsuo 
Published: July 2006

Abstract
Macroreticular styrene-divinylbenzene copolymers functionalized with iminodiacetic acid and diethylenetriamine-N,N,N″,N″-tetraacetic acid have been examined in order to apply them to the selective recovery of gallium(III) and/or indium(III) from acidic solutions. The equilibrium adsorption capacities, distribution coefficients, and metal-adsorption rates of the polymer resins for Group IIIb ions and other common metal ions have been studied. The selectivity sequence of the present resins are as follows: Fe(III)&gt;In(III)&gt;Ga(III)\simeqCu(II)&gt;Zn(II)&gt;Al(III). The selective recovery of In(III) and/or Ga(III) from acidic solutions has been demonstrated using a column of the present resins.
2-Allylisourea as an Effective Agent for Direct α-Allylation of Ketone and Aldehyde Assisted by Palladium(0) under Neutral Conditions
Authors: Inoue Yoshio , Toyofuku Masanori , Taguchi Masaaki , Okada Shin-ichi , Hashimoto Harukichi 
Published: July 2006

Abstract
Direct α-allylation of a variety of ketones and aldehydes with 2-allylisourea took place in the presence of a catalytic amount of a palladium(0) complex under neutral and mild conditions. Scope and limitations of this novel method have been investigated.
Replacement of the Activated Nitro Group by a Phenylthio Group
Authors: Miyake Hideyoshi , Yamamura Kimiaki 
Published: July 2006

Abstract
The nitro group, activated by a carbonyl group, alkoxycarbonyl group or a phenyl group, can be replaced by a phenylthio group in the reaction with benzenethiol or its potassium salt. This reaction proceeds in the electron transfer mechanism, and is applicable to the general syntheses of α-phenylthio ketones, α-phenylthio carboxylic esters and α-phenylthio alkylbenzenes from primary nitro compounds.
Electron-Transfer-Initiated Photoreactions of 1-Methyl-2-phenyl-1-pyrrolinium Perchlorate with α-Heteroatom-Substituted Alkanoate Anions
Authors: Kurauchi Yoshiaki , Nobuhara Hideo , Ohga Kazuya 
Published: July 2006

Abstract
The irradiation of aqueous solutions of 1-methyl-2-phenyl-1-pyrrolinium perchlorate (1) in the presence of α-hydroxyalkanoate anions led to the formation of 2-(hydroxyalkyl)pyrrolidine adducts and a reduction product, 1-methyl-2-phenylpyrrolidine. Mechanistic studies demonstrated that photoaddition reactions were induced by one-electron transfers from the carboxylato groups of alkanoates to the excited singlet state of 1 (1S1), followed by an efficient decarboxylation. Furthermore, the photoreaction of 1 with ethoxyacetate was found to give a 2-(ethoxymethyl)pyrrolidine adduct in preference to the reduction product. For photoreactions with 2-mercaptopropionate and α-amino acids, the reduction product was detected. N-Acetylglycinate gave a 2-(acetylaminomethyl)pyrrolidine adduct in fairly high yield (80%). The features of these photoreactions with α-heteroatom-substituted alkanoates are discussed in terms of fluorescence-quenching efficiencies and the properties of radicals formed through electron transfers to 1S1.
Photoionization Threshold Energies of Amine Solutions Studied by Photoelectron Emission by Solution
Authors: Watanabe Iwao , Maya Keiichi , Yabuhara Yoshiki , Ikeda Shigero 
Published: July 2006

Abstract
The threshold energies Et of photoelectron emission by solutions (PEES) were determined for several butylamines in acetonitrile and water. The correlations between Et and gas-phase ionization potential Ip and oxidation potential Eox were found to be linear. The difference between Et and Ip originates from the electronic polarization energy of solvent molecules and the polarization energy was found to be inversely proportional to the solvation radius in accordance with the Born solvation free energy model. The Et values were also compared with Eox to discuss the reorientation relaxation of solvent molecules in the electron transfer process. The selective coverage of aqueous solution surface with amine molecule was indicated by the PEES technique.
Generation of the Selenonium Ylide by the Carbenic Reaction. Formation of Cyclopropane Derivatives via Selenonium Ylide
Authors: Ibata Toshikazu , Kashiuchi Makoto 
Published: July 2006

Abstract
The Cu(acac)2-catalyzed decomposition of α-diazoacetophenones in the presence of bis(p-methoxyphenyl) selenide (3) did not give the corresponding selenonium ylide but gave r-1,c-2,t-3-tribenzoylcyclopropanes through the successive reaction of the intermediary selenonium ylide. On the other hand, the reaction of diazodimedone with 3 gave bis(p-methoxyphenyl)selenonium 4,4-dimethyl-2,6-dioxocyclohexylide.
Kinetic Studies of Fast Equilibrium by Means of High-Performance Liquid Chromatography. XIII. Separation of Rotamers of N-Alkyl-Substituted Amides
Authors: Moriyasu Masataka , Kato Atsushi , Hashimoto Yohei 
Published: July 2006

Abstract
Rotamers of N-alkyl-substituted amides have been separated by means of high-performance liquid chromatography(HPLC) at low column temperatures. The ratios of the E-rotamers have been found to increase in the following order: propionamides&lt;acetamides&lt;formamides.
Ion-Chromatographic Determination of Valproic Acid
Authors: Itoh Hisaaki , Shinbori Yoshio , Tamura Norihiro 
Published: July 2006

Abstract
A new direct chromatographic assay method of valproic acid (2-propylpentanoic acid) using a carbonic acid solution as the eluent and conductivity detection was developed and applied to its determination in Depakene tablets and human plasma. The analytical recovery and the coefficients of variation of the method obtained by the use of drug-free plasma samples spiked with various amounts of valproic acid were ranged from 96.5 to 104% and from 3.2% at 12.4μg cm−3 to 0.8% at 124μg cm−3, respectively. No interference from the plasma constituents or from other anticonvulsants was observed. The procedure is simple, fast, specific, and precise. The plasma levels of valproic acid obtained from patients receiving sodium valproate together with other anticonvulsants are indicated.
A General Synthetic Method of Chiral 2-Arylalkanoic Esters via Thermal 1,2-Rearrangement
Authors: Honda Yutaka , Ori Aiichiro , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
(S)-1-Aryl-2-sulfonyloxy-1-alkanone acetals, prepared from natural ethyl (S)-lactate or (S)-valine (chiral sources) by the use of a Grignard reaction, were rearranged under hydrolytic conditions in the presence of a base to give (S)-2-arylalkanoic esters which, in general, showed much higher pharmacological activities than their antipodes.
Free Radical Addition of 2-Bromoalkanoic Acids to Alkenes
Authors: Nakano Taichi , Kayama Mikio , Nagai Yoichiro 
Published: July 2006

Abstract
The benzoyl peroxide-catalyzed reaction of 2-bromoalkanoic acids such as bromoacetic, 2-bromopropionic, and 2-bromobutyric acid with 1-alkenes was found to proceed through the addition of the C–Br bond across the double bond followed by cyclization affording 4-alkanolides in good yields.
The Transformation of Cyclic Alcohols into Cyclic Acetals through a New Oxygen Atom Insertion by Photolysis in the Presence of Lead Tetraacetate and Iodine
Authors: Suginome Hiroshi , Washiyama Haruka , Yamada Shinji 
Published: July 2006

Abstract
Photolysis of the hypoiodites of steroidal cyclic homoallyl alcohols such as cholesterol and of cyclic alcohols such as 5α-androstan-17β-ol generated in situ in benzene with three molar equivalents each of lead tetraacetate and iodine was found generally to result in the unprecedented formation of corresponding lactol acetates in yields up to 66%. The lactol acetates are readily hydrolysed to lactols in most cases during their isolation and lactols are isolated products. Thus, cholesterol gave 4-oxa-A-homocholest-5-en-3-ol and its acetate in a 53% yield. The products differ considerably from those reported by us after the photolysis of the hypoiodites by using mercury(II) oxide and iodine as the reagents for generating the hypoiodites; they also differ from those in the oxidation of the steroidal alcohols with lead tetraacetate alone. The photolysis of the hypoiodite of 2,2-dimethyl-5β-cholestan-3-ol was found to lead to the formation of an anomalous lactol, 2α-iodomethyl-2β-methyl-4-oxa-A-homo-5α-cholestan-4ξ-ol together with normal lactol. We discuss the paths of the formation of the lactol acetates involving β-scission of the alkoxyl radicals. A new process was found in the photolysis of 2-indanol hypoiodite in the presence of lead tetraacetate and iodine. Our previously suggested pathways to the formation of 3α,5-epoxy-6-iodo-4-oxa-A-homo-5α-cholestanes and 3-formyloxy-2-iodo-2,3-seco-A-norcholest-5-ene in the photolysis of cholesterol hypoiodite in the presence of mercury(II) oxide and iodine were supported by the results of the photolysis of 4-oxa-A-homocholest-5-en-3-ol hypoiodite in the presence of mercury(II) oxide and iodine.
Stereoselective Synthesis of Octadecapolyenoic Esters as an Insecticide
Authors: Tsuboi Sadao , Wu Xue Han , Maeda Seiji , Ono Shinichiro , Kuroda Akihisa , Kawazu Kazuyoshi , Takeda Akira 
Published: July 2006

Abstract
Octadecapolyenoic acid derivatives such as (±)-t-butyl coriolate, α-eleostearic acid, t-butyl punicate, and t-butyl (9Z,11E)-13-hydroxy-9,11-octadecadien-15-ynoate were synthesized starting from oleic acid with high stereoselectivity and their insecticidal activity was examined.
New Liquid Crystalline Homologous Series Exhibiting the Smectic C Phase
Authors: Sakagami Sakumitsu 
Published: July 2006

Abstract
A liguid crystalline homologous series of N-[4-(4-alkoxybenzoyloxy)benzylidene]-4-butylanilines and their hydroxyl derivatives at the 2-position were synthesized, and then the liquid-crystalline-phase transitions were determined using a differential scanning calorimeter and a polarizing microscope. All of the members exhibit a nematic phase, and a smectic C phase can be observed for the homologues with a relatively long alkoxyl chain.
Kinetics of the Solubilization of Pinacyanol Chloride into a Complex between Bovine Serum Albumin and Sodium Dodecyl Sulfate
Authors: Takeda Kunio , Ohtawa Tohru , Hachiya Kazuaki , Aoki Koichiro 
Published: July 2006

Abstract
The stopped-flow method was applied to the solubilization of pinacyanol chloride into a complex formed by bovine serum albumin and sodium dodecyl sulfate. The rate constant of the solubilization became larger with the step-by-step formation of the complex and finally attained values compatible with those for the pure surfactant micelle.
Cobalt(III) Complexes with [N6−nXn]-Type Ligands. VI. The Preparation and Properties of Tetraammine(salicylamidato)cobalt(III) Complexes
Authors: Yamamoto Yoshihisa , Shinya Noriko 
Published: July 2006

Abstract
Tetraammine(salicylamidato)cobalt(III) complexes, (Remark: Graphics omitted.)) (X: Cl, NO3 and picrate), have been isolated and characterized by means of analytical, spectroscopic, and magnetic methods. The bond between the cobalt atom and the chelated ligand in the complex is expressed in the form of –\barO–Co–\barN–. The properties of the title complexes are intermediate between those of the tetraammine(salicylideneaminato)cobalt(III) complex, which has the –\barO–Co–N– bond, and the tetraammine(salicylato)cobalt(III) complex, which has the –\barO–Co–\barO– bond.