bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Addition Reaction of Substituted Benzenesulfinic Acids to N-Phenylmaleimide
Authors: Matsuda Itsuo , Akiyama Keiichi , Furuta Hiroyuki , Mizuta Masateru 
Published: July 2006

Abstract
The reaction of substituted benzenesulfinic acids with N-phenymaleimide has been carried out, and the products obtained have been identified as sulfones from analyses of their IR, UV, and NMR spectra. From the kinetic investigation, a linear Hammett relationship between the σ-value and logK2/K0 has been confirmed. It is concluded that the nucleophilic attack of the sulfinic acid sulfur atom on the carbon of the C=C bond of N-phenylmaleimide is the rate-determining step.
Synthetic Studies on Quinoxaline Antibiotics. II. Synthesis of Triostin A
Authors: Shin Masaru , Inouye Ken , Otsuka Hideo 
Published: July 2006

Abstract
Triostin A, a cyclic octadepsipeptide, was synthesized with Z–d-Ser[Boc–Ala–MeCys(Bzl)–MeVal]–OH and Z–d-Ser[H–Ala–MeCy(Bzl)–MeVal]–OTce as key intermediates. The synthetic antibiotic was compared with natural triostin A in terms of chromatographic behaviors, NMR spectra, and antimicrobial activity to establish their identity. The NMR data on S,S′-dibenzyldihydrotriostin A showed that this intermediate lacking the disulfide linkage also existed as two conformers in chloroform. This observation excludes the possibility that the conformer equilibrium known to occur with triostin A is a consequence of the reversed chirality of the disulfide bond.
Kinetic Studies of the Oxidation of 2,3-Dihydroxy-2-propenal (Triose Reductone) by the Peroxodisulfate Ion
Authors: Abe Yasuo , Horii Hideo , Taniguchi Setsuo 
Published: July 2006

Abstract
Kinetic studies of the oxidation of 2,3-dihydroxy-2-propenal (triose reductone) by the peroxodisulfate ion (S2O82−) were carried out between pH 4.1 and 5.9 at various temperatures (10–30°C) and for ionic strengths (I) (0.07 to 1.07 M (1 M=l mol dm−3)) which were adjusted using NaClO4. The pH dependence of the reaction rates revealed that the singly-charged anion (RH−) was chiefly responsible for the reaction, while undissociated reductone was inactive to peroxodisulfate ion. The rate constant (k2) of RH− with S2O82− was 0.79 M−1 s−1 at 25°C and I=1.07 M (ΔH\eweq=37 kJ mol−1, ΔS\eweq=−123 J deg−1 mol−1). A relationship of logk2=−0.95±1.88I1⁄2⁄(1+I1⁄2) was found at 30°C.
Photoreduction of 2-Benzoylalkanoates
Authors: Yoshioka Michikazu , Aoki Satoshi , Shimizu Toshio , Hasegawa Tadashi 
Published: July 2006

Abstract
2-Benzoylalkanoates 1 undergo photoreduction with 2-propanol. The photoreduction products are classified into three types according to their origin: the homo-pinacol-type products 2, 5, 7, and 8, the mixed-pinacol-type product 3, and the β-hydroxy ester 6. The product distribution is affected by α-methyl substitution. The α-methyl substitution decreases the percentage of the homo-pinacol-type products and increases the percentage of the β-hydroxy ester.
Conduction Band Formation through the Temporary Anion States in Organic Solids
Authors: Hiraoka Kenzo , Nara Masaji 
Published: July 2006

Abstract
The transmission of low-energy electrons (0–15 eV) through thin films of benzene, toluene, pyridine, aniline, styrene, and cyclohexene was studied. The electron transmission spectra of all the aromatic compounds studied are like each other in their forms. The energies of several prominent peaks in the electron transmission spectra are in good agreement with those of temporary anion states measured in the gas phase. It is suggested that vacant orbitals of free molecules form conduction bands in molecular crystals.
Redox Behavior and Electrochromic Properties of Polypyrrole Films in Aqueous Solutions
Authors: Kuwabata Susumu , Yoneyama Hiroshi , Tamura Hideo 
Published: July 2006

Abstract
Polypyrrole films prepared by anodic polymerization of pyrrole on Pt or SnO2-coated glass show redox behavior in aqueous electrolyte solutions containing a supporting electrolyte alone. Transfer of electrolyte anions into and from the film is involved in the redox reaction similarly with acetonitrile solutions already reported. Insertion of divalent anions into the film occurs in two steps but that of monovalent anions in one step, as judged from corresponding cyclic voltammograms. The change in film color which occurs in the redox reaction of the film was investigated in detail as a function of electrode potential and the charge consumed in the redox reaction. Polypyrrole is a promising material for electrochromic display devices.
The Complex Formation of Organomercury with 8-Quinolinol
Authors: Kuniya Joji , Naito Kunishige , Takei Shinsuke 
Published: July 2006

Abstract
Organomercury(II)(RHg+, R; ethyl, n-propyl, n-butyl) forms two kinds of water-soluble complexes, RHgq and RHg(q)(OH)−, with 8-quinolinol(oxine Hq). These complex-formation reactions are studied by means of spectrophotometry, and the formation constants of these complexes, RHgOH, RHgOAc, and RHg(OH)(OAc)−, in 4%(v/v) ethanol at the ionic strength of 0.1 are determined. Reliable results are obtained for ethylmercury(II) and n-propylmercury(II) complexes.
A General Synthetic Approach of Spirovetivanes. The Synthesis of (±)-Solavetivone, (±)-Hinesol, and Related Compounds
Authors: Murai Akio , Sato Shingo , Masamune Tadashi 
Published: July 2006

Abstract
The synthetic procedure leading to preparation of representative compounds, (±)-solavetivone and (±)-hinesol, of two classes of spirovetivanes, is described. The procedure involves Diels-Alder reaction of 4-substituted 5,6-dihydro-3,5-dimethylanisoles with methyl acrylate and π-cyclization of 4-(2-mesyloxyethyl)-4-prenyl-2-cyclohexen-1-one as key steps (Scheme 1).
Kinetics and Mechanism of Dissociation of (Acetylacetonato)[N-(o-carboxyphenyl)iminodiacetato]chromate(III) Ion in Acidic Media
Authors: Chatterjee Chinmay , Bali Aya Singh 
Published: July 2006

Abstract
Acid-catalyzed dissociation of (acetylacetonato) [N-(o-carboxyphenyl) iminodiacetato]chromate(III) ion has been studied kinetically in aqueous perchloric acid media over a temperature range (60–80 °C). Under these conditions the reaction occurs by two concurrent paths according to the following rate law: Rate=k1[complex]+k2[complex][H+], where k1 and k2 are the appropriate rate constants for the spontaneous and acid-catalyzed pathways, respectively Analysis of the rate data corresponding to the rate constants k1 and k2 suggests solvent assisted dissociation of the complex and its conjugate acid for the two paths, respectively, and that the opening of the chelate ring is rate determining.
Pentane Isomerization Activity of Halogenated Rare Earth Intermetallics
Authors: Imamura Hayao , Kato Yuzo , Tsuchiya Susumu 
Published: July 2006

Abstract
Binary halides formed by treating ErAl3 with halogen elements were subjected to an characterization as skeletal isomerization catalysts for pentane. Halogenation of ErAl3 in the presence of CH2Cl2 or CCl4 gives rise to super-acidic binary halides as a result of formation of V-center-type sites due to excess of halogen species.
Indexing of X-Ray Powder Diffraction Data for Potassium Hexafluorovanadate(III)
Authors: Koyama Koichiro , Hashimoto Yasuhiko , Omori Shinichiro , Terawaki Kazuo 
Published: July 2006

Abstract
X-Ray powder diffraction data for K3VF6 are presented; the α form is monoclinic with a=1.2102(1), b=1.7456(2), c=1.2007(2) nm, β=92.58(1)° at 298K; the β form is monoclinic with a=1.714(2), b=1.237(1), c=0.5479(2) nm, β=91.49(3)° at 453 K; the γ form is tetragonal with a=1.3708(5), c=0.8752(5)nm at 483 K; the low-temperature γ form, which contains a small amount of sodium ion, is tetragonal with a=1.3570(3), c=0.8671(2) nm at 298 K.
The Catalytic Properties of the Pd/Mica Model Catalyst
Authors: Takasu Yoshio , Kasahara Kenji , Matsuda Yoshiharu 
Published: July 2006

Abstract
The apparent activation energy of an H2–D2 exchange reaction on a Pd/mica model catalyst system increased with the decrease in the particle size of palladium. The activity pattern as a function of the mean particle size was of a volcano-type, with a maximum at a particle size around 1.2 nm.
Dielectric Relaxation of Some Aliphatic Ketones in Dilute Solution
Authors: Singh Buta 
Published: July 2006

Abstract
Measurements of the relative permittivity at frequency of 10 GHz, and of the refractive index, have been made at 25 °C for (a) 2-haxanone, (b) 3-hexanone, (c) 3-Methyl-2-pentanone, (d) 3,3-dimethyl-2-butanone, (e) 2-heptanone, (f) heptanal, and (g) cyclohexanone, in dilute solutions of cyclohexane, decalin, and 1,4-dioxane, Dielectric relaxation times have been evaluated. It has been concluded that in the ketones and heptanal under study, dipole reorientation occurs mainly by an intramolecular relaxation process.
Kinetics of Copper(II) Incorparation in a Porphyrin Using Four Copper Salts
Authors: Datta-Gupta Nirmalendu , Malakar Debasis , Datta-Gupta Sukla , Gibson Richard 
Published: July 2006

Abstract
Using excess of acetate, chloride, bromide, and sulfate salts, the kinetics of Cu(II) incorporation in meso-tetrakis (4-benzyloxyphenyl) porphyrin, in DMF solution, at different temperatures, have been done. The thermodynamic parameters have been calculated and a mechanism of Cu(II) insertion proposed.
The Synthesis of Polymeric Catalyst Using Ion Exchange Resin and Its Application for Esterification
Authors: Whang Kyu-Ja , Lee Keun-Im , Lee Yong-Keun 
Published: July 2006

Abstract
The copolymer complexes have been synthesized from cation and/or anion resin with metal catalyst such as aluminum chloride or iron(III) chloride. Electron microprobe X-ray analysis demonstrated that aluminum and iron were distributed uniformly in the copolymer complex. The catalytic activity for esterification of dibasic organic acids was discussed and showed that copolymer complex from porous type cation exchange resin was much better catalyst than that from gel type.
Electrochemical Properties of Adriamycin Adsorbed on a Mercury Electrode Surface
Authors: Kano Kenji , Konse Tomonori , Nishimura Naomi , Kubota Tanekazu 
Published: July 2006

Abstract
The electrochemical behavior of adriamycin has been studied by means of cyclic d.c. and a.c. voltammetry with a hanging mercury drop electrode, quinizarin being used as a model compound. Both adriamycin and quinizarin are strongly adsorbed on the mercury electrode with their aromatic ring planes oriented parallel to the electrode surface, and give two sets of reduction waves. The first wave, due to the quinone moieties of the adsorbed adriamycin and quinizarin, has been explained on terms of a two-step one-electron surface redox reaction. The formal standard redox potentials, semiquinone formation constants, and charge transfer rate constants of the surface redox reaction of the quinone moieties have been determined. Although the reduced form of adriamycin is not very stable chemically, it is converted to a stable and electrochemically active form for a few minutes at pH 4.54. The second wave appearing at more negative potential would be due to a kinetic or catalytic process.
13C-NMR Studies on Conformational Equilibria in Isopropyl Methyl Ether
Authors: Tasaki Kenzabu , Sasanuma Yuji , Ando Isao , Abe Akihiro 
Published: July 2006

Abstract
The energy difference between the two rotational isomers, i.e., Cs and C1, of isopropyl methyl ether has been elucidated from the observed vicinal 13C-1H coupling constant. The conventional Gutowsky method based on the simple rotational isomeric state model tends to give an underestimate, especially when the energy difference is large. A more elaborate treatment, which takes account of the overall profile of the torsional potential energy curve, has been attempted. Adoption of JT=11.0–12.0 Hz for the trans coupling gave a value of 2.2±0.2 kcal mol−1 for the energy difference Ecs–Ec1. This result is consistent with the range (2.4±0.6 kcal mol−1) estimated by the matrix-isolation method as reported by Nakata et al.
The Microwave Spectrum of Acrylaldehyde Oxime
Authors: Niwase Manabu , Kubota Kyoko , Yoshida Kazuhiko , Sakaizumi Takeshi , Onda Masao , Ohashi Osamu , Yamaguchi Ichiro 
Published: July 2006

Abstract
The microwave spectra of acrylaldehyde oxime and its deuterated derivative (CH2=CH–CH=NOD) were observed in the frequency region from 8.5 to 35 GHz. The several a-type R-branch transitions in the ground vibradonal state were identified and the following rotational constants in MHz were determined to be: A=34117±96, B=2363.007±0.011, and C=2210.616±0.011 for normal species and A=33950±103, B=2274.301±0.010, and C=2131.981±0.011 for deuterated species. The most plausible molecular structure to which the spectrum assigned is attributed has been deduced to be a s-trans syn geometrical conformer from the rotational constants experimentally determined. The dipole moment component μa in the ground vibrational state was determined to be 0.59 D from the Stark effects of J=2←1 transitions. The rs coordinates of the OH hydrogen atom have been determined and the orientation of the OH bond in the molecule has been discussed.
Ruthenium Catalyzed Reduction of Nitroarenes and Azaaromatic Compounds Using Formic Acid
Authors: Watanabe Yoshihisa , Ohta Tetsuo , Tsuji Yasushi , Hiyoshi Takao , Tsuji Yasuo 
Published: July 2006

Abstract
Various nitroarenes having chloro, methyl, or methoxy substituents were reduced to the corresponding aminoarenes in high yields using formic acid in the presence of a catalytic amount of RuCl2(PPh3)3. For example, 4-chloronitrobenzene was converted in 99% conversion with 98% selectivity at 125 °C for 5 h. 4-Nitroacetophenone was reduced chemoselectively to 1-(4-nitrophenyl)ethanol in 74% isolated yield under the same reaction conditions. Formic acid could also be employed as reductant for hydrogenation of heterocyclic compounds such as quinoline, indole, and quinoxaline in the presence of the ruthenium catalyst. 2-Methylquinoline was hydrogenated to 1,2,3,4-tetrahydro-2-methylquinoline in 93% conversion with 100% selectivity.
Preferred Conformations of cis-4-Hydroxy-2-chromancarboxylates and Related Compounds. Molecular Force Field Interpretation
Authors: Hirota Minoru , Abe Kazuhisa , Shibata Masamichi , Suezawa Hiroko , Hanaya Kaoru , Muramatsu Takashi , Ikegami Yusaku 
Published: July 2006

Abstract
In contrast to cis-4-hydroxy-2-tetralincarboxylates, cis-4-hydroxy-2-chromancarboxylates take diaxial conformation having 4-pseudoaxial-OH and 2-axial-COOR groups preferably. The preferred conformations of these compounds were rationalized by molecular force field (MM 1/MMP 1) calculations on the corresponding 2-tetralin- and 2-chromancarbaldehydes as model compounds.
N-Hydroxy Amides. II. N-Benzyloxy α-Amino Acid N-Hydroxysuccinimide Esters and Synthesis of a Hexapeptide Having an Alternating N-Hydroxy Amide–Amide Sequence
Authors: Shimizu Kazuyuki , Nakayama Kazuyuki , Akiyama Masayasu 
Published: July 2006

Abstract
Acylation of a series of N-benzyloxy α-amino acid derivatives with N,N-phthaloyloglycine shows that the yield decreases with increasing bulkiness of the substituent even by the acyl chloride or mixed anhydride procedure, and that the use of an excess reagent or a double acylation technique is needed to attain a good yield. The low reactivity of the benzyloxyamino group enables us to utilize N-benzyloxy α-amino acid N-hydroxysuccinimide esters without N-protection in the acylation of the usual amino group. In an attempt to lengthen the chain of an N-hydroxy peptide, a hexapeptide anilide having an N-hydroxy-Dl-alanylglycyl sequence was synthesized via N-benzyloxy peptides. The complex forming tendency of the hexapeptide with iron(III) is examined.
Stereoelectronic and Homoconjugative Effect of Stereoselectivity. The Addition of Dichlorocarbene to 1,5-Dimethyl-6-methylenetricyclo[3.2.1.02,7]oct-3-en-8-one and Its Related Compounds
Authors: Nitta Makoto , Okada Shuji , Kato Masami 
Published: July 2006

Abstract
The reaction of dichlorocarbene with 1,5-dimethyl-6-methylenetricyclo[3.2.1.02,7]oct-3-en-8-one, its corresponding alcohol derivative, and 1,5,8-trimethyl-6-methylenetricyclo[3.2.1.02,7]oct-3-en-8-endo-ol occurs on the exocyclic double bond to give exo and endo adducts with preferential formation of the exo adduct. Dichlorocarbene addition to 1,3,5-trimethyl-6-methylenetricyclo[3.2.1.02,7]oct-3-en-8-one (1d) occurs on the endocyclic double bond from the exo side, while the reaction occurs on the exocyclic double bond from both the exo and endo sides in the case of the corresponding alcohol derivative. The stereoselectivity or site selectivity was discussed on the basis of the stereoelectronic and homoconjugative effects as well as the steric effect of the reaction. Several chemical transformations, along with the derivation of bis adducts of dichlorocarbene, were also studied for confirmation of the structure of mono adducts. 1,3-Dipolar cycloaddition of 1d and its dichlorocarbene adduct with mesitonitrile oxide, giving the adducts on the exocyclic double bond, was also studied to suggest a possible causative factor to control the electrophilic addition in the indicated direction.
A New Wittig Rearrangement of 2,2-Disubstituted 1,3-Dithianes
Authors: Ikehira Hideyuki , Tanimoto Shigeo 
Published: July 2006

Abstract
Carbanions produced by deprotonation at the ring C-4 of 2,2-disubstituted 1,3-dithianes undergo a Wittig type rearrangement to give the anions of 2,2-disubstituted tetrahydrothiophene-3-thiols. After being trapped with several alkyl halides, these afford the corresponding 2,2-disubstituted 3-(alkylthio)tetrahydrothiophenes, which are difficult to prepare by other synthetic routes.
Constituents of Seeds of Ailanthus altissima Swingle. Isolation and Structures of Shinjuglycosides A, B, C, and D
Authors: Yoshimura Shin , Ishibashi Masami , Tsuyuki Takahiko , Takahashi Takeyoshi , Matsushita Kazuhiro 
Published: July 2006

Abstract
Four bitter quassinoid glycosides, shinjuglycosides A, B, C, and D were isolated from seeds of Ailanthus altissima Swingle and their structures were established to be 2-β-d-glucopyranosides of chaparrin, shinjulactone A, amarolide 11-acetate, and amarolide, respectively, from spectral data and enzymatic or acid-catalyzed hydrolysis.
The Reaction of Primary Nitro Compounds with Dipolarophiles in the Presence of p-Toluenesulfonic Acid
Authors: Shimizu Tomio , Hayashi Yoshiyuki , Teramura Kazuhiro 
Published: July 2006

Abstract
3-Substituted 2-isoxazolines or isoxazoles were obtained from the reaction of primary nitro compounds [methyl nitroacetate, 2-nitro-1-phenylethanone, (nitromethyl)benzene, 1-nitropropane, and (phenylsulfonyl)nitromethane] with dipolarophiles in refluxing mesitylene in the presence of a small amount of p-toluenesulfonic acid. The formation of these products can be explained in terms of 1,3-dipolar cycloaddition of nitrile oxide generated by a dehydration of the primary nitro compounds. On the other hand, 4,5-decamethylene-3-phenylsulfonyl-2-isoxazoline N-oxide was obtained from a similar reaction of (phenylsulfonyl)nitromethane with cyclododecene. The formation of the isoxazoline N-oxide can be explained on the basis of the intermediacy of 3,4-bis(phenylsulfonyl)furazan 2-oxide.
Hydrogenation and Hydrogenolysis. XVII. The Selectivities of Platinum Group Metals in Catalytic Hydrogenation of 2-Naphthol and Tetrahydro-2-naphthols
Authors: Nishimura Shigeo , Ohbuchi Shin-ichi , Ikeno Kiyoshi , Okada Yasuhiro 
Published: July 2006

Abstract
Catalytic hydrogenation of 2-naphthol (NL) with the six platinum metals has been studied in t-BuOH at 80 °C and 4–5 MPa H2 pressure. Selectivities for formation of 1,2,3,- and 5,6,7,8-tetrahydro-2-naphthols (ac- and ar-TLs) have been determined by application of a kinetic equation. ar-TL was formed more predominantly than ac-TL over all the metals. The hydrogenation of ac- and ar-TLs has also been studied under the same conditions for comparison. The hydrogenation of NL and ar-TL was accompanied by extensive hydrogenolysis to give decalins over Os, Ir, and Pt, whereas the hydrogenolysis occurred only slightly over Ru, Rh, and Pd. In general the hydrogenolysis occurred to much lesser extents with ac-TL. The amounts of 2-decalone formed in hydrogenation of ar-TL have been determined by application of the kinetic equation. The 2-decalone was the cis isomer only except with Pd. For formation of the cis products at the ring juncture, hydrogenation of ar-TL was highly stereoselective with Ru, Rh, Os, and Ir, while hydrogenation of ac-TL was the most stereoselective with Os and Ir. The course of hydrogenolysis and the stereochemistry of hydrogenation are discussed from the comparative results on NL, ar-TL, and ac-TL.
The Viscosity Coefficients of 18-Crown-6–Alkali Metal-ion Complexes
Authors: Kawaizumi Fumio , Yajima Isao , Nomura Hiroyasu , Miyahara Yutaka 
Published: July 2006

Abstract
The viscosities of LiCl, KCl, and CsCl have been measured in water and aqueous solutions containing 0.398 mol/dm3 of 18-crown-6 (CR) at 25 °C. The B-coefficients of the alkali metal chlorides in water have been obtained using the theoretical values of the A-coefficients. The viscosity coefficients of 18-crown-6 itself have been determined in water and methanol. In systems containing crown ether, the viscosity increment due to the complex formed in solutions, Δη[CR–M+]Cl−, has been evaluated by subtracting from the observed viscosity the increment attributed to non-coordinated crown ether and alkali metal chlorides in solutions. The two complex ions, [CR-K+] and [CR-Cs+], have nearly the same values of the B-coefficients, and these values are, in turn, approximately equal to that of 18-crown-6 in water. Measurements done on KCl in methanol containing 18-crown-6 have led to the finding that in methanol, 18-cown-6 and the [CR-K+] ion take effectively the same B-value.
The Structure of Liquid Alcohols by Neutron Diffraction. II. Molecular Structure of Ethyl Alcohol
Authors: Tanaka Yukio , Ohtomo Norio , Arakawa Kiyoshi 
Published: July 2006

Abstract
The structure factor Sm(Q) for liquid ethyl alcohol (C2D5OD) at room temperature was obtained by means of the time-of-flight (TOF) neutron diffraction method using electron LINAC. An analysis of the diffraction data was carried out and the molecular structure in liquid phase was determined as follows: the O–D,C–O, and C–C bond lengths are 0.960±0.010 Å, 1.410±0.010 Å and 1.510±0.010 Å, respectively.
The Structure of the Cyclodextrin Complex. XVII. Crystal Structure of β-Cyclodextrin–Hexamethylenetetramine (1:1) Complex Hexahydrate
Authors: Harata Kazuaki 
Published: July 2006

Abstract
The crystal structure of β-cyclodextrin–hexamethylenetetramine (1:1) complex hexahydrate was determined by the X-ray diffraction method. The crystal ismonoclinic with the space group P21, Z=2, a=15.285(3), b=10.345(2), c=20.118(2) Å, and β=102.14(1)°. The structure was solved by inspection of a Patterson map and the trial-and-error method combined with the rigid-body least-squares technique and refined by the block-diagonal least-squares method to the R-value of 0.056 for 4369 reflections (sinθ⁄λ&lt;0.55). The β-cyclodextrin molecule is slightly distorted from the regular heptagonal structure. The orientation of two primary hydroxyl groups is statistically disordered. The secondary hydroxyl groups form intramolecular hydrogen bonds between adjacent glucose residues. The guest hexamethylenetetramine molecule, being located roughly at the center of the β-cyclodextrin ring, is in van der Waals contact with the interior surface of the host molecule. Two out of four nitrogen atoms of hexamethylenetetramine form N···H–O hydrogen bonds with water and adjacent β-cyclodextrin molecules. β-Cyclodextrin molecules are stacked along the crystallographic b axis, with which the plane through seven glycosidic oxygen atoms makes an angle of 46.7°, forming a “cage-type” packing. Water molecules occupy the intermolecular spaces between β-cyclodextrin molecules.