bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereoselectivity in Mixed Ligand Copper(II) Complexes with Electrostatic Ligand-Ligand Interactions. Application to Optical Resolution of α-Amino Acids with a Charged Side Chain
Authors: Yamauchi Osamu , Sakurai Takeshi , Nakahara Akitsugu
Published: July 2006

Optical resolution of Dl-aspartic acid and Dl-glutamic acid (abbreviated as Dl-A) has been achieved via formation of ternary copper(II) complexes composed of a Dl-A and l-arginine, l-lysine, or l-ornithine (l-B). For every pair of ligands Dl-A and l-B, a neutralized solution containing Cu(ClO4)2, Dl-A, and l-B in the molar ratio of 1 : 2 : 1 gave the mixed ligand complex abounding in [Cu(d-A)(l-B)] as crystals, from which incorporated A was isolated through a Dowex CCR-2 column after treating with H2S. In a very similar manner d-enantiomerrich B was obtained from Dl-B by using an l-A. The optical purities of the resolved amino acids were as high as 90 and 70% for aspartic acid and glutamic acid, respectively, and 40–50% for the basic amino acids. The finding shows that the electrostatic ligand-ligand interactions in the mixed ligand complexes give rise to geometric isomerism around copper(II) and hence preferential formation and crystallization of the meso complexes, [Cu(l-A)(d-B)] and [Cu(d-A)(l-B)], probably with a cis configuration.
13C NMR Spectroscopy. Substituent Effects in the Ethyl trans-2-Substituted Cyclopropanecarboxylates
Authors: Kusuyama Yoshiaki , Ikeda Yoshitsugu
Published: July 2006

13CFT NMR spectra have been obtained for ethyl trans-2-substituted cyclopropanecarboxylates. The chemical shifts have been compared with those of saturated and unsaturated compounds and with substituent constants. The chemical shifts of the methylene carbon of the ethyl group have been correlated linearly with σm.
The Intramolecular OH···π Bonding in [n]Paracyclophanols
Authors: Mori Nobuo , Takemura Tetsuo , Ohkuma Takayoshi
Published: July 2006

The intramolecular OH···π bonding, the probable conformations, and the internal rotation in two series of [n]paracyclophanols, I (1–4) and II (5–8), are investigated by means of IR, UV, and PMR spectroscopies. The IR results indicate that (1) there is the OH···π bonding in 1, 2, 3, 5, and 7 in CCl4, and (2) the integrated intensity ratio of the π-bonded OH species to the free OH, (Ab/Af), hardly changes in going from 1 to 3, while it decreases in going from 5 to 7. The ratio is, then, related to both ΔH and ΔS. In the PMR spectra, aliphatic-proton signals are assigned by means of the spin-decoupling and/or the shift-reagent technique; the results agree with those predicted, with a few exceptions. In the aromatic region, 3, 4, and 8 show singlets, while the others show AB-like quartets. These results are discussed in relation to the internal rotation of the benzene ring and/or the alkylene chain.
Photochemical Reactions between Dibromomaleic Anhydride and Benzo[b]thiophene
Authors: Matsuo Taku , Mihara Satoru
Published: July 2006

On the irradiation of dibromomaleic anhydride in the presence of benzo[b]thiophene, both photosubstitution and photocycloaddition are simultaneously induced. The ratio of the substituted product to the cycloadduct increased with solvent polarity, and the same Stern-Volmer plots were obtained with both of the reactions. Kinetic parameters, obtained under various concentrations of benzo[b]thiophene, indicate that the reactions proceed via a common triplet exciplex. The activation energy for the photosubstitution is higher than that for the cycloaddition by 1–2 kcal/mol, where the former reaction is considered to proceed via a more polar transition state than the latter.
Layered Compounds. XLII. Syntheses and Properties of Layered Paracycloheterophanes
Authors: Otsubo Tetsuo , Mizogami Shigeyoshi , Osaka Norihisa , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

A series of multilayered paracyclofuranophanes and paracyclothiophenophanes were synthesized by crossbreeding Hofmann elimination method from mixed quaternary ammonium hydroxides. Their structures and conformations were elucidated by NMR analyses. In electronic spectra, paracyclothiophenophanes exhibited stronge transannular electronic interactions than paracyclofuranophanes whose absorption curves show unexpected resemblance to those of multilayered metaparacyclophanes. Paracyclofuranophanes and [2.2](2,5)furanophane underwent addition reaction with benzyne to give 1 : 1 and 1 : 2 adducts, respectively. Their structures and properties were also studied by spectral measurements.
Total Synthesis of Minosaminomycin
Authors: Iinuma Katsuharu , Kondo Shinichi , Maeda Kenji , Umezawa Hamao
Published: July 2006

A component of the antibiotic minosaminomycin (1), (−)-1d-1-amino-1-deoxy-myo-inositol (4) was synthesized from d-inositol (3) by catalytic oxidation of an axial hydroxyl group followed by reduction of the ketoxime. Minobiosamine, 1d-1-amino-1-deoxy-4-O-(α-d-kasugaminyl)-myo-inositol (2), was synthesized from 2′,4′-di-N-acetylkasuganobiosamine (9) by a similar method, and separated from the two isomers of 2. The total synthesis of 1 was accomplished by coupling 2′,4′-di-N-benzyloxycarbonylminobiosamine (14) and Nα-[(S)-1-benzyloxycarbonyl-3-methylbutylcarbamoyl]enduracididine (15) followed by removal of the protective groups. Compound 14 was derived from 1,2′,4′-tri-N-benzyloxycarbonylminobiosamine through the formation of the cis-1,2-carbamate. A diastereomer of 1 was also synthesized using alloenduracididine.
Preparation and Resolution of (4-Aminobutanoic acidato)bis(ethylenediamine)cobalt(III) Ion
Authors: Kojima Masaaki , Takayanagi Hiromichi , Fujita Junnosuke
Published: July 2006

A new complex containing a seven-membered chelate ring, [Co(amb)(en)2]2+ (amb=4-aminobutanoato ion) was prepared and resolved. The complex is decomposed in 1.0 M HClO4 at room temperature to give [Co(H2O)(Hamb)(en)2]3+ in which the Hamb acts as a unidentate ligand with a free carboxyl group.
Synthesis of Manninotriose Undecaacetate
Authors: Adachi Ryoichi , Suami Tetsuo
Published: July 2006

Manninotriose undecaacetate has been prepared from melibiose. Tritylation of melibiose, followed by acetylation gave 6′-O-trityl-β-melibiose heptaacetate. Detritylation of the compound gave hepta-O-acetyl-β-melibiose, which was condensed with tetra-O-benzyl-d-galactopyranosyl chloride. Deacetylation of the condensation product, followed by hydrogenolysis and acetylation afforded the title compound.
Syntheses with 2-Furylmagnesium Bromides. I. Synthesis of Rosefuran and Sesquirosefuran
Authors: Takeda Akira , Shinhama K\={o}ichi , Tsuboi Sadao
Published: July 2006

The preparation and reactions of 2-furylmagnesium bromide and 3-methyl-2-furylmagnesium bromide (4b) have been studied. Activated 90% magnesium–copper alloy was used to prepare the Grignard reagents. The reaction of 1-bromo-3-methyl-2-butene with 4b gave rosefuran in a 40% yield; that of geranyl bromide with 4b gave sesquirosefuran in a 26% yield.
Multielement Analysis of Deep-Sea Sediments by Photon Activation
Authors: Kato Toyoaki , Sato Nobuyoshi , Suzuki Nobuo
Published: July 2006

A nondestructive photon activation with 30 MeV bremsstrahlung has been applied to the multielement determination in the pelagic sediments in a region of the Pacific Ocean. The abundances for 6 major and 10 trace elements were measured in several deep-sea floors and the core samples, discussion being given on the results. Determination of trace elements such as Cr, Co, Ni, and Sr is valuable because of their geochemical significance.
Potentiomeric and Polarographic Studies on Complex Formation of Cadmium(II) Ion with Ethylenediaminemonoacetic Acid
Authors: Oyama Noboru , Horie Masashi , Matsuda Hiroaki , Ohtaki Hitoshi
Published: July 2006

The complex formation equilibria between Cd(II) ion and ethylenediaminemonoacetic acid (EDMA) were examined by potentiometry in a 1.0 mol dm−3 NaClO4 solution at (25.00±0.02) °C, and it was found that neither protonated nor hydrolyzed complex was formed in the range of pH from 2 to 10. The formation constants of Cd(II)–EDMA complexes as well as the protonation constants of EDMA anion determined were as follows: logβ101=6.86, logβ102=12.32; logβ011=9.97, logβ021=16.71, logβ031=18.76, where βpqr=[MpHqLr]/[M]p[H]q[L]r. The formation constants were also examined polarographically.
Semiintegral Electroanalysis in the Absence of Supporting Electrolyte
Authors: Goto Masashi , Grenness Morten , Oldham Keith B
Published: July 2006

The limiting semiintegral of the current which flows when a stationary electrode is progressively polarized in the presence of electroactive species has been investigated under the condition of no supporting electrolyte present in the solution. The semiintegral, m(t), of the current, i(t), is defined by

m(t)=\fracd^-1/2dt^-1/2i(t)=\frac1π^1/2∫_0^t\fraci(λ)(t-λ)^1/2dλ.

The electroreduction of a number of heavy metal ions has been studied at a mercury drop electrode and it was found that the limiting semiintegral is larger than that observed with excess supporting electrolyte present. The finding is in agreement with a simple theory which considers both diffusion and migration mass transfer processes. The factor by which the limiting semiintegral increases has been shown to depend on the diffusion coefficients and charge numbers of the cation and anion.
Structure and Characterization of Copper(II) and Nickel(II) Complexes with 3-Acetyl-5,6-dimethylpyridazine Hydrazone, the Condensation Product of Biacetyl and Hydrazine
Authors: Okawa Hisashi , Matsumoto Naohide , Kida Sigeo
Published: July 2006

Copper(II) and nickel(II) complexes, MLX2·nH2O (L=C16H24N8; X=Cl−, Br−, NO3−, ClO4−, BF4−; n=0, 2), were obtained by reacting diacetyl with hydrazine in the presence of a metal ion and characterized. The condensation product L was found to be 3-acetyl-5,6-dimethylpyridazine hydrazone. The molecular structure of NiL(ClO4)2·2H2O has been determined, the configuration around the nickel(II) ion being a distorted octahedron.
Photoreaction of 4-Substituted Quinoline N-Oxide and 2(1H)-Quinolinone in Propionic Acid
Authors: Ide Akio , Mori Yukinori , Matsumori Kunihiko , Watanabe Hiroyasu
Published: July 2006

4-Substituted cis-3-ethyl-2-oxo-1,2,3,4-tetrahydro-2-quinoline was formed as a major product, by irradiation of quinoline N-oxide and 2(1H)-quinolinone substituted with an electron-withdrawing group at the C-4 position in propionic acid. Also, the products were confirmed by direct comparison with synthesized compounds.
Chemical Studies on Tuberactinomycin. XI. Semisyntheses of Tuberactinomycin Analogs with Various Amino Acids in Branched Part
Authors: Wakamiya Tateaki , Teshima Tadashi , Sakakibara Hideo , Fukukawa Kiyoshi , Shiba Tetsuo
Published: July 2006

Thirty two semisynthetic tuberactinomycins were prepared by introduction of various amino acids to amino group of tuberactinamine N, a cyclic peptide moiety of tuberactinomycin N and O, which was isolated from natural tuberactinomycin N by acid treatment with liberation of γ-hydroxy-β-lysine of the branched part. Among introduced amino acids, β-amino acids were synthesized from corresponding α-amino acids by modified Arndt-Eistert reaction. After couplings of N-protected amino acids with tuberactinamine N, deprotections were carried out to give semisynthetic tuberactinomycins. From their minimum inhibitory concentrations against many bacteria, it was suggested that a branched part effects significantly to the strength of antimicrobial activities though most important active site must locate in the cyclic peptide moiety, and basicity and/or hydrophobicity of the branched part seemed to strengthen the antibacterial activity especially.
Studies of Peptide Antibiotics. XXXV. Synthesis of Gramicidin S by a Fragment Solid-Phase Method
Authors: Sato Kazuki , Abe Hayao , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

In order to examine the usefulness of a fragment condensation procedure in solid-phase peptide synthesis, gramicidin S (GS) was synthesized by three different procedures such as stepwise elongation, fragment condensation with dipeptide fragments, and fragment condensation with tripeptide fragments. The two fragment condensation procedures gave intermediate peptide derivatives in high yields and in high purity. Such differences in the purity of the intermediate peptides disappeared in the final product, GS dihydrochloride. The GS synthesized by the three procedures exhibited the same antibacterial activities as those of natural GS.
Reaction of Coordinated Phosphines. III. Reaction of Phenyl Compounds of Typical Groups V and VI Elements with Palladium(II) Salts in the Presence of Olefinic Compounds
Authors: Kawamura Teruo , Kikukawa Kiyoshi , Takagi Makoto , Matsuda Tsutomu
Published: July 2006

The reaction of phenyl compounds of typical groups V and VI elements, PhnA and PhnAX2 (n=2, 3; A=P, As, Sb, Bi, S, Se, Te; X=Cl or X2=O), with Pd(II) salts was studied in the presence of olefinic compounds (1-octene and ethyl acrylate) in acetonitrile. The phenyl migration from A to Pd to produce phenylpalladium species, which lead to the phenylation of olefin, was observed for all PhnA and PhnAX2 (except for A=S and Ph3PX2) when Pd(OAc)2 was utilized. The reaction, however, was inhibited or greatly suppressed for the compounds of P and As when PdCl2 was used in place of Pd(OAc)2. The compounds of Sb and Bi readily react with PdCl2. Mechanistic discussion was given in terms of the extent of nucleophilic assistance by acetate ion when Pd(II) attacks the aromatic nucleus electrophilically at the carbon atom bonded to A.
Synthesis and Absolute Stereochemistry of (+)-6,15-Dihydro-6,15-ethanonaphtho[2,3-c]pentaphene as Determined by Exciton Chirality and X-Ray Bijvoet Methods
Authors: Harada Nobuyuki , Takuma Yuki , Uda Hisashi
Published: July 2006

(6R,15R-(+)-6,15-Dihydro-6,15-ethanonaphtho[2,3-c]pentaphene (1) was synthesized from (9R,10R)-(+)-dimethyl 9,10-dihydro-9,10-ethanoanthracene-1,5-dicarboxylate, the absolute configuration of which has been established by the X-ray Bijvoet method and chemical correlations. The CD spectrum of 1 clearly exhibits very strong positive first and negative second Cotton effects due to coupling of the 1Bb transitions (Δε268.0=+931.3 and Δε249.7=−720.8; A(=Δε1–Δε2)=+1652.1), the positive sign of the A value being in accord with the positive exciton chirality between the two long axes of the anthracene moieties in 1. The results demonstrate an ideal case of chiral exciton coupling in CD spectra, and provide evidence of the consistency between nonempirical CD exciton chirality and X-ray Bijvoet methods.
Formation of a Charge-Transfer Complex between the 1-Methyl-1-phenylethylperoxyl Radical and Pyridine during Decomposition of 1-Methyl-1-phenylethyl Hydroperoxide
Authors: Fukuzumi Shun-ichi , Ono Yoshio
Published: July 2006

The apparent rate constant for the self-reaction of 1-methyl-1-phenylethylperoxyl radicals (RO2.) in the presence of pyridine was determined from simultaneous measurements of the rate of oxygen generation and the concentration of the peroxyl radical during the decomposition of 1-methyl-1-phenylethyl hydroperoxide with lead dioxide. The apparent rate constant decreased markedly with an increase in the concentration of pyridine, which clearly demonstrates the low reactivity of RO2· in the presence of pyridine. This behavior is taken as evidence that the charge-transfer complex between the peroxyl radical and pyridine is formed and that the reactivity of complexed peroxyl radicals is much lower than that of uncomplexed peroxyl radicals. The equilibrium constant for the formation of the charge-transfer complex has been determined to be 0.55 M−1 at 293 K and the values of −ΔH and −ΔS were found to be 31 kJ mol −1 and 109 J mol−1 K−1, respectively.
Mechanism of the Photochemical Ring Expansion of N-Vinyl-2-pyrrolidone. Estimation of the Recombination-Time of Biradical
Authors: Shizuka Haruo , Ogiwara Toshio , Morita Toshifumi
Published: July 2006

The photochemical ring expansion of N-vinyl-2-pyrrolidone (NVP) has been carried out at 254 nm. The reaction quantum yield depends a great deal on the solvnet viscosity and temperature. The recombination time of the biradical of RP produced by Norrish type I fission was estimated to be ≈10−10 s by application of the Einstein and Smoluchowski-Debye equations. The spin inversion of the biradical in a solvent cage is also discussed according to Kaptein’s theory of the radical-pair mechanism.
ESR and ENDOR Studies of the Ion Pairs of Double-, Triple-, and Quadruple-layered [2.2]Paracyclophane Radical Anions and Alkali Metal Cations
Authors: Iwaizumi Masamoto , Kita Shouichi , Isobe Taro , Kohno Masahiro , Yamamoto Takamitsu , Horita Hisanori , Otsubo Tetsuo , Misumi Soichi
Published: July 2006

The radical anions of double-, triple-, and two kinds of quadruple-layered [2.2]paracyclophane XX\ewdot, XDX\ewdot, XDDX(C2h)\ewdot and XDDX(D2)\ewdot were examined by means of ESR and ENDOR spectroscopy. The spin distributions in these radical anions are largely polarized by interaction with counter ions. An MO calculation has been attempted to account for the observed ion-pairing effects. It is shown by the calculations that the observed ion-pairing effects can be explained by the ion-pair models where the cation is located above the center of the outermost benzene ring. It is also shown that the potassium ion migrates from one side of the radical molecule to the other in a loosely bound ion pair of XDX\ewdot in a 1,2-dimethoxyethane(DME)-tetrahydrofuran(THF) 1:1 mixed solvent, as in the ion pair of XX\ewdot with the potassium ion in DME-THF (2:1) which has been previously reported by Gerson et al. Such migration of cations in ion pairs was not observed for the quadruple-layered [2.2]paracyclo-phane radical anions.
Fluorescence and Laser Photolysis Studies on the Intramolecular Exciplex Systems in Micellar Solutions
Authors: Masuhara Hiroshi , Kaji Katsumi , Mataga Noboru
Published: July 2006

The behavior of intramolecular exciplex systems consisting of pyrene and N,N-dimethylaniline was studied in cationic, anionic and neutral micellar solutions. These systems are favorable for the study of photoinduced CT interaction in micellar systems, since (i) a pair of donor-acceptor is always solubilized in the micelle and (ii) the complicated effect of the intermolecular interaction can be prevented. No exciplex emission was detected and relative quantum yields as well as lifetimes were measured on the monomer fluorescence. The results are interpreted by assuming two solubilized forms in the micelle-water interface. Efficient quenching occurs in the dodecyltrimethylammonium chloride solution irrespective of the length of the methylene chain, suggesting a different solubilization from the cases of other detergents. The efficient quenching is ascribed to the rapid ion-pair formation in the micelle-water interface, which was directly demonstrated by the ns laser photolysis method.
The Structural Role of the Aluminum Ion in Alkali Aluminophosphate Glass Containing Less Than 50 mol% of P2O5
Authors: Kishioka Akira
Published: July 2006

Several series of alkali (Na and K) aluminophosphate glasses with a constant P2O5 content of less than 50 mol % were prepared. From the infrared absorption spectra of these glasses, and also from the paper chromatograms of aqueous solutions of these glasses, we obtained the following results: The PO43− ion increased with an increase in the amount of Al2O3 when the P2O5 content was kept constant. The PO43−/P2O5 ratio in the glass increased with an increase in the Al2O3 content, whereas it decreased with an increase in the P2O5 content. In the composition of 32.5 mol % of P2O5, the glass containing exclusively PO43−-type ions as a phosphate species was found. The PO43−/Al3+ ratio was smaller than unity in the case of a lower Al2O3 content and larger than unity in the case of a higher Al2O3 content. From these results, the structural role of the Al3+ ion can be revealed as follows: In the glass with a lower Al2O3 content, two kinds of Al3+ ions exist–(1) the Al3+ ion, which forms the P–O–Al linkage by the substitution of the P5+ ion in the P–O–P linkage, and (2) the Al3+ ion, which does not form such a linkage, whereas in the glass with a higher Al2O3 content all the Al3+ ions substitute the P5+ ion to form the P–O–Al linkage.
Evaluation of PAC, TAC, 2-IAC as Metallochromic Indicators in the EDTA Titrations of Nickel
Authors: Wada Hiroko , Nakazawa Osamu , Takada Hajime
Published: July 2006

The rates of color change of 2-(2-pyridylazo)-4-methylphenol (PAC), 2-(2-thiazolylazo)-4-methylphenol (TAC) and 2-(2-imidazolylazo)-4-methylphenol (2-IAC) during EDTA–nickel titration have been determined. The rate is a thousand times greater for TAC and 2-IAC than for PAC. From equilibrium considerations, the rate of color change and the color contrast change, an evaluation of PAC, TAC, and 2-IAC as metallochromic indicators for nickel is given. The optimum pH ranges with TAC and 2-IAC are from 6 to 7 and from 5 to 7, respectively, at 80 °C. With PAC, the titration should be conducted with boiling at pH 4–5. 2-IAC is the best indicator due to the good visual color contrast and the wide pH range over which it is applicable.
Preparation of Optically Active 1,3-Diphenyl-1,3-propanediamine (dppn) and the Circular Dichroism of trans-[CoCl2-(S,S-dppn)2]+ and [Co(S,S-dppn)3]3+
Authors: Arakawa Sumio , Kashiwabara Kazuo , Fujita Junnosuke , Saito Kazuo
Published: July 2006

1,3-Diphenyl-1,3-propanediamine (dppn) was prepared from 1,3-diphenyl-2-propen-1-one. The meso and racemic isomers were isolated. The racemate was resolved into enantiomers with (+)D-di-O-benzoyltartrate. The absolute configuration of the free diamine was determined by comparing the circular dichroism (CD) spectrum of trans-[CoCl2(S,S- or R,R-dppn)2]+ with that of trans-[CoCl2(R,R-2,4-pentanediamine)2]+. The absolute configurations of Δ- and Λ-[Co(S,S-dppn)3]3+ were also assigned on the basis of the CD spectra.
Infrared Spectra of 1,3-Butadiene Adsorbed on Alumina-supported Metal Catalysts at Various Temperatures
Authors: Soma Yuko
Published: July 2006

The infrared spectra of 1,3-butadiene adsorbed on Pd, Ni, and Co catalysts were measured while changing the adsorption temperature. These catalysts behaved differently in butadiene adsorption, and π-adsorbed butadiene was the major adsorbed species below 0 °C on Pd and Ni. This π-species was easily hydrogenated to produce butene at the same temperature.
Determination of Magnetic Susceptibilities of Diamagnetic Liquids by an Improved Viscometer Method
Authors: Sueoka Kazuo , Ikeda Toshio
Published: July 2006

An improved viscometer method is presented for the determination of the magnetic susceptibility of a liquid with a complete exclusion of the oxygen effect. The method was found to be excellent even in determining the magnetic susceptibilities of diamagnetic liquids, giving results accurate to within ±0.05%. The influence of air (or oxygen) was also discussed.
Hydrogen Isotope Effect on the Radical Addition of the Hydrogensulfite Ion to Allyl Alcohol in Aqueous Solutions
Authors: Miyata Teijiro , Sakumoto Akihisa , Washino Masamitsu
Published: July 2006

A study of the radiation-induced addition of HSO3− to allyl alcohol was carried out in D2O–H2O mixtures. It was found that a linear relationship held between the apparent rate constant of NaHSO3 consumption and the atom fraction of deuterium in the mixture, and that the hydrogen atom abstraction from HSO3− by HOCH2\dotCH-CH2SO3− was the rate-determining step. The kinetic isotope effect of this abstraction was 4.38.
Rhodium Complex Catalyzed Hydrogenation of α,β-Unsaturated Aldehydes to Unsaturated Alcohols
Authors: Mizoroki Tsutomu , Seki Katsumi , Meguro Shun-ichi , Ozaki Atsumu
Published: July 2006

Rhodium complexes were found to be effective in catalyzing selective hydrogenation of cinnamaldehyde to cinnamyl alcohol in the presence of strongly basic amine such as triethylamine or N-methylpyrrolidine under oxo reaction conditions. The selectivity of analogous hydrogenation of aliphatic unsaturated aldehyde was poorer than that of aromatic aldehyde. When a catalytic amount of triphenylphosphine was added, the selectivity was drastically changed to exclusive formation of hydrocinnamaldehyde. In order to elucidate the nature of rhodiumamine interaction, Rh2Cl2(CO4) was immobilized on a cross-linked chloromethylated polystyrene which was functionalized with pyrrolidine, the polymer amine acting as a tertiary amine. The polymer–rhodium complex was found to be stable and to effect the selective hydrogenation of cinnamaldehyde, while addition of triphenylphosphine seemed to liberate the rhodium complex from the polymer. It is concluded that a rhodium–amine–carbonyl complex is responsible for the selective hydrogenation of α,β-unsaturated aldehyde to the unsaturated alcohol.
Preparation of 5,5-Bis(ethoxycarbonyl)-5,6-dihydro-3,7-diaryl-4H-1,2-diazepines and Their Halogenations
Authors: Tsuge Otohiko , Kamata Kichinosuke , Yogi Seiichi
Published: July 2006

5,5-Bis(ethoxycarbonyl)-5,6-dihydro-3,7-diaryl-4H-1,2-diazepines (4) were prepared by the condensation of α-bromoacetophenone azines with diethyl malonate in the presence of sodium ethoxide. Halogenation of 4 afforded 7,7-bis(ethoxycarbonyl)-2,5-diaryl-3,4-diazanorcaradiene, 4,6-dihalodihydrodiazepines, 1-halodiazanorcaradienes, and/or 4,4,6,6-tetrachlorodihydrodiazepine, whose relative yields depended upon the reaction conditions. Dehalogenation of the halogenated products was also investigated.
The Absolute Configuration of Sepiapterin
Authors: Matsuura Sadao , Sugimoto Takashi , Tsusue Motoo
Published: July 2006

The absolute configuration of sepiapterin was determined to be 2-amino-7,8-dihydro-6-(S)-lactoyl-4(3H)pteridinone from an analysis of the l-lactic acid produced from sepiapterin by oxidation cleavage in a sodium borate solution.
The Intramolecular Hydrogen Abstraction Reaction in the Photolysis of Aminated 1,4-Naphthoquinones
Authors: Maruyama Kazuhiro , Kozuka Tadashi , Otsuki Tetsuo
Published: July 2006

Photolysis of aminated 1,4-naphthoquinones 1a–c in liquid phase was investigated. After photolysis and successive autoxidation, 2-(3-pyrrolin-1-yl)-1,4-naphthoquinone 1a gave 2-(1-pyrrolyl)-1,4-naphthoquinone 3 quantitatively. However, in the reaction, 2-(1-pyrrolydinyl)-1,4-naphthoquinone 1b and 2-(2-methoxycarbonyl-1-pyrrolidinyl)-1,4-naphthoquinone 1c afforded the corresponding hetero-ring opened products; 2-(4-oxobutylamino)-1,4-naphthoquinone 5 and 2-(4-methoxycarbonyl-4-oxobutylamino)-1,4-naphthoquinone 8 in good yields. Possible mechanisms for the formation of 3, 5, and 8 are presented.
A Semi-empirical NDDO Method for All-valence-electron Systems. II. Extension to Compounds Containing Nitrogen and/or Oxygen
Authors: Kikuchi Osamu , Maeda Akira
Published: July 2006

A semi-empirical NDDO method is extended to compounds containing nitrogen and/or oxygen, and is applied to the evaluation of the molecular geometries and excitation energies of the compounds and of the heats of reactions relating to them. The agreement between the calculated and observed values is comparable with that previously attained for hydrocarbons except for the conformations of NH3 and CH3NH2.
Light Induced Tritiation of Methyl Benzoate with Diethylamine-N-t and Triethylamine–Tritiated Water Mixture
Authors: Kitamura Akihide , Kaneko Hiroyuki , Morikawa Naotake , Oohashi Kunio , Sakuragi Hirochika , Tokumaru Katsumi , Umeda Mamoru , Yoshida Masayuki
Published: July 2006

Methyl benzoate was tritiated at both nuclear and methyl positions on irradiation with diethylamine-N-t in benzene and with triethylamine–tritiated water in acetonitrile.
5-Fluorouracil Derivatives. II. A Convenient Synthesis of 5-Fluoro-2′-deoxyuridine
Authors: Ozaki Shoichiro , Katakami Tsutomu , Saneyoshi Mineo
Published: July 2006

The reaction of 5-fluorouridine with propionyl bromide in acetonitrile afforded 3′,5′-di-O-propionyl-2′-bromo-5-fluoro-2′-deoxyuridine (2). Compound 2 was then hydrogenated, using Pd–C as the catalyst, to afford 3′,5′-di-O-propionyl-5-fluoro-2′-deoxyuridine (3). Compound 3 was deacylated with methanolic ammonia to give 5-fluoro-2′-deoxyuridine (FUDR). In this way, FUDR, a good antitumor agent, can easily be prepared from 5-fluorouridine by three steps in a 48.9% total yield.
Singlet Excitation Energy Transfer in the Vinyl Polymers with Pendant Carbazolyl Groups
Authors: Itaya Akira , Okamoto Ken-ichi , Kusabayashi Shigekazu
Published: July 2006

The migration of electronic excitation energy in films of poly(N-vinylcarbazole) (PVCz) prepared by the radical and cationic polymerizations(PVCz(r) and PVCz(c) respectively), poly[2-(9-carbazolyl)ethyl vinyl ether] (PCz-EVE), brominated PVCz(BPVCz), and poly(9-acryloylcarbazole) (PACz) has been studied by means of fluorescence-quenching experiments, using dimethyl terephthalate or perylene as a guest molecule. No clear difference in the concentration of the effective intrinsic trap sites was observed between PVCz(r) and PVCz(c) films. The concentration of the sandwich-like excimer site(cE) in a PVCz(r) film was nearly equal to that in a PVCz(c) film, while the concentration of the second excimer site (cS) in a PVCz(r) film was higher than that in a PVCz(c) film by a factor of about 1.6. The value of cE was much larger than that of cS for both films. The second excimer site seems to be a shallow trap. The number of carbazolyl chromophores covered by a singlet exciton during the lifetime was in the following order: PCzEVE>PVCz(r)≈PVCz(c)>PACz≈BPVCz. This order was explained by the concentration of the intrinsic trap sites depending on the distance between neighboring Cz chromophores, the lifetime of the singlet exciton, and the concentration of extrinsic trap sites.
The Efficient Oxidation of Thiols to Disulfides with Thallium(III) Acetate
Authors: Uemura Sakae , Tanaka Sakuya , Okano Masaya
Published: July 2006

The treatment of various kinds of alkane- and arenethiols with thallium(III) acetate in chloroform at 20–30 °C readily affords the corresponding disulfides almost quantitatively, without affecting other functional groups, such as the hydroxyl, amino, and carboxyl in the thiols. Under similar conditions, the reaction of thiobenzoic S-acid with thallium(III) acetate gives thallium(III) thiobenzoate, while that of thioacetic S-acid yields diacetyl disulfide and thallium(I) thioacetate.
Photo-induced Cycloaddition of 1-Nitrocyclooctene and Cyclopentadiene
Authors: Yokoyama Keiichi , Katô Masao , Noyori Ryoji
Published: July 2006

Irradiation of 1-nitrocyclooctene produces first the strained trans isomer, which in turn undergoes thermal Diels-Alder reaction with cyclopentadiene affording the tricyclic adduct.
Photolysis of Benzenesulfonic Acid
Authors: Ogata Yoshiro , Takagi Katsuhiko , Yamada Shin
Published: July 2006

Photolysis of benzenesulfonic acid(1) in an aqueous solution gave sulfurous acid, SO2, and/or sulfuric acid as inorganic products in a total yield of 38.6% based on the consumed 1 along with organic products. The organic products are mainly acidic tarry material containing sulfur(8.7%) together with a small amount of biphenyl (1%). Photolysis of an alkaline solution of 1 afforded a considerable amount of benzene (16%) and biphenyl(<1%). The photolysis is started by the C–S bond fission of 1 to give Ph· and ·SO3H radicals. The quantum yield for decomposition of 1 in acidic conditions is 0.26.
14N Nuclear Quadrupole Resonances of the Molecular Complexes of Urea
Authors: Negita Hisao , Kubo Tsuneo , Maekawa Michio
Published: July 2006

The 14N nuclear quadrupole resonance (NQR) was studied on three kinds of molecular complexes of urea, such as the urea–hydrogen peroxide complex (H2O2 complex), the urea–sodium chloride–water complex (NaCl complex), and the urea–sodium bromide–water complex (NaBr complex). The 14N quadrupole coupling constants and asymmetry parameters are as follows: |e2Qq⁄h|=3493.8 kHz and η=0.3456 for the H2O2 complex; |e2·Qq⁄h|=3597 kHz and η=0.293 for the NaCl complex, and |e2Qq⁄h|=3636.7 kHz and η=0.2778 for the NaBr complex. From the temperature dependence of the resonance frequencies, it is considered that the hydrogen bonds in the H2O2 complex are stronger than those in the NaCl complex. The electron densities at nitrogen atoms in these complexes were derived from the corresponding NQR parameters, and were compared with those in urea.
Proton Transfer between Styrene Molecular Anion and Ethanol in Rigid Organic Matrices
Authors: Noda Shoji , Fujii Yasumi , Yoshida Hiroshi
Published: July 2006

The proton transfer from ethanol to styrene molecular anion was studied by examining the yield of the anion and α-methylbenzyl radical generated in γ-irradiated 2-methyltetrahydrofuran–ethanol mixed matrix at 77 K by means of optical absorption measurements. The radical yield was found to increase in proportion to the ethanol fraction at the expense of the anion yield. The maximum radical yield, 2.2, was identical with the yield of scavengeable electron in ethanol matrix where no anion was observed. Upon photobleaching the anion was transformed into the radical in the matrix. The transformation efficiency was constant, ca. 0.6, for the ethanol fraction 0.3–0.9. It is concluded that the radical arises from the anion through the proton transfer from ethanol to the β-carbon of vinyl group of the styrene anion. The proton transfer occurs readily only when a specific solvent site around the anion is populated by ethanol molecules. Otherwise, the proton transfer does not occur at all because of the restricted translational motion in the rigid matrix.
Ultrasonic and Volumetric Investigation of Aqueous Solutions of Amides
Authors: Kawaizumi Fumio , Ohno Makoto , Miyahara Yutaka
Published: July 2006

The ultrasonic velocity and density of aqueous solutions of N-methylformamide, N,N-dimethylformamide, and N,N-dimethyIacetamide have been measured at 25 and 35 °C over the entire concentration range. The compressibility, excess compressibility, partial molar compressibility, partial molar volume, and pressure dependence of the partial molar volume have been calculated. The concentration dependences of the velocity and density are highly nonlinear, and the velocity maxima are observed in all the amide solutions at ca. 20 mol%. Minima in the partial molar volume exist in solutions of DMF and DMAA, but not in that of MFA. On taking account of the results for viscosity, the velocity maxima are ascribed to the complex formation, and the minima in the partial molar volume, to the competition between the volume increase due to the complex formation and the volume decrease due to the breaking-down of the water structure. The pressure dependence of the partial molar volume shows that amides and water have strong interactions, even in the low-mole-fraction regions for each component.
Threshold Switching in Anthracene Thin Films
Authors: Sadaoka Yoshihiko , Sakai Yoshiro , Kishi Kohhei
Published: July 2006

Threshold switching was observed in anthracene thin films (<3 μm) using a circuit with a high protective resistance. On the other hand, when the protective resistance was small, the switching was erratic and irreproducible. In the latter case, the switching was occasionally accompanied by filamentary damages caused by the excess current focused at the electrically weak spots, and the threshold voltage was poorly dependent on the protective resistance. The threshold-switching characteristics for thin films are interpretable in terms of the transition from the trap-limited SCLC to the trap-filled SCLC. The thermal breakdown model is not adaptable.
Surface Oxidation of the Thin Films of Polycyclic Aromatic Hydrocarbons Studied by X-Ray Photoelectron Spectroscopy
Authors: Yamada Masamichi , Ikemoto Isao , Kuroda Haruo
Published: July 2006

The oxidation of the surfaces of thin films of perylene, pentacene, violanthrene, and mesonaphthodianthrene on exposure to oxygen or to the air was studied by means of X-ray photoelectron spectroscopy. A perylene film was found to be the least reactive toward oxygen among the above four hydrocarbons. In the cases of pentacene and violanthrene films, a single, broad O 1s peak grew up with time over the period of a few months as the exposure to the air was prolonged. On exposure to oxygen, a mesonaphthodianthrene film exhibited the O 1s spectrum which apparently consisted of two peaks located at the binding energies, 531.0 and 532.9 eV respectively, and the peak at 532.9 eV reduced its intensity irreversibly on heating the film in a high vacuum, suggesting that it was the one associated with a loosely bound oxygen.
Vibration Spectra and Rotational Isomerism of Chain Molecules. VI. 2-Chloro-, 2-Bromo-, and 2-Iodoethyl Methyl Ethers
Authors: Matsuura Hiroatsu , Kono Motomichi , Iizuka Hiroshi , Ogawa Yoshiki , Harada Issei , Shimanouchi Takehiko
Published: July 2006

The Raman and infrared spectra of 2-chloro-, 2-bromo, and 2-iodoethyl methyl ethers, CH3OCH2CH2X (X=Cl, Br, and I), were measured for the liquid, glassy, and crystalline states. The gaseous-state spectra of the chloride were also measured. The vibrational frequencies of these molecules were calculated by the use of the force constants transferred directly from unbranched ethers and alkyl halides. The rotational isomerism was studied and the following conclusions were obtained. (1) In the crystalline state, the molecule takes the form having the trans conformation about the CO–CC axis and the gauche conformation about the OC–CX axis. (2) In addition to this form (TG), three other forms (GG, TT, and GT) exist in the gaseous, liquid, and glassy states. (3) In the liquid state, the TG form is the most stable and the GT form is the least stable. (4) The less polar TT and GT forms are more favored and the more polar TG and GG forms are less favored in the gaseous state than in the liquid state.
Chromium(III) Complexes with Amino Acids. III. Chromium(III) Complexes with Acidic, Basic and Carbamoyl Amino Acids
Authors: Oki Hisaya , Takahashi Yasuko
Published: July 2006

Syntheses by both the isothermal matrix in a solid state and by the usual solution method have been tried for chromium (III) complexes with l- and Dl-asparagine, l- and Dl-aspartic acid, l- and Dl-glutamine, l- and Dl-glutamic acid, l- and Dl-lysine, and l-ornithine. [Cr(l-aspNH2)3]·2H2O, [Cr(Dl-aspNH2)3]·3H2O, (NH4)2[Cr(l-asp)2][Cr(d-asp)2]·4H2O, and (+)[Cr(l-lys)2(NH3)(H2O)]Cl·4H2O were obtained by the matrix method in the solid state, while [Cr(l-aspNH2)3]·2H2O, [Cr(Dl-aspNH2)3]·2H2O, and (+)[Cr(l-lys)2(NH3)(H2O)]Cl·4H2O were prepared by the usual solution method. The preparation of chromium(III) complexes with other amino acids was not successful. A new type of complex of chromium(III) containing terdentate Dl-aspartic acid and a new mixed chromium(III) complex containing three different ligands (l-lysine, ammine, and aqua) were prepared.
Determination of Rubidium in Biological Materials Using Atomic Absorption Spectroscopy
Authors: Tanaka Gi-ichiro , Tomikawa Akeo , Kawamura Hisao
Published: July 2006

In order to establish a reliable and rapid method for the determination of rubidium in biological materials using atomic absorption spectroscopy, chemical interference as well as ionization interference due to co-existing elements and some organic substances was studied. In the presence of potassium of sufficient concentration, most of the interference was found to be negligible. The temperature of the sample solutions proved to be a possible source of error. The process of sample preparation was examined, including a determination of the loss of rubidium in dry ashing. The accuracy and precision of the method was tested by analyzing NBS SRM 1577 Bovine Liver. The rubidium contents of typical biological materials—foodstuffs, human tissues and urine— were determined by the present method and a possible relationship between the rubidium and potassium concentrations is indicated.
Synthesis of a Lividomycin B Analogue, 5-O-[3-O-(2-Amino-2-deoxy-α-d-grlucopyranosyl)-β-d-ribofuranosyl]-3′-deoxyparomamine
Authors: Watanabe Isamu , Tsuchiya Tsutomu , Takase Tsuneyuki , Umezawa Sumio , Umezawa Hamao
Published: July 2006

5-O-[3-O-(2-Amino-2-deoxy-α-d-glucopyranosyl)-β-d-ribofuranosyl]-3′-deoxyparomamine was prepared by two different routes. The first route involves glycosylation of a protected N : 6-O-carbonyl-3′-deoxyparomamine with a protected 3-O-(2-amino-2-deoxy-α-d-glucopyranosyl)ribofuranosyl bromide and subsequent removal of the protecting groups. In the second route, 1-N : 6-O-carbnyl-3′-deoxyparomamine was glycosylated with a protected ribosyl bromide having 3-O-benzylthiocarbonyl group to give a pseudotrisaccharide and, after de-3-O-benzylthiocarbonylation, the product was further condensed with a protected 1-bromide of 2-amino-2-deoxy-d-glucose. This synthesized lividomycin B analogue showed only very weak antibacterial activity and the role of the 6'″-amino group of lividomycin in the action was suggested.
Reduction by a Model of NAD(P)H. XV. Kinetics for the Reduction of Methyl Benzoylformate
Authors: Ohno Atsuyosi , Yamamoto Hiroyuki , Okamoto Tadashi , Oka Shinzaburo , Ohnishi Yutaka
Published: July 2006

Kinetics for the reduction of methyl benzoylformate (1) with N-α-methylbenzyl-1-propyl-1,4-dihydronicotinamide (2) in the presence of magnesium perchlorate in acetonitrile at 25 °C has been studied. The reaction follows first-order in 1, first-order in 2, and zero-order in magnesium ion when [2]<<[1], [Mg(ClO4)2]. When [2]= [Mg(ClO4)2]<<[1], the kinetics is best explained by Eqs. 6 and 7. The results indicate that 2 and magnesium ion form a complex, which reacts with 1 at the rate-determining step. It is concluded that magnesium ion activates 2 to promote the release of an electron.
Synthesis of α Substance-IB in Saccharomyces cerevisiae
Authors: Aoyagi Haruhiko , Izumiya Nobuo
Published: July 2006

Two hexapeptides, H–Arg–Gly–Pro–Phe–Pro–Ile–OH (1a) and H–Arg–Pro–Gly–Phe–Pro–Ile–OH (1b), have been proposed for a factor inducing sexual agglutination in the yeast and were synthesized by a conventional method. Compound 1a was completely identical with the natural peptide in thin-layer chromatography, mass spectrometric measurements, and biological assay on agglutination. Compound 1a showed the same biological activity as 1a though distinct differences in the chemical data were observed. Strong bitterness of the 1a and 1b was discovered.
New Method for Synthesis of Various Types of Substituted 2(5H)-Furanones
Authors: Iwai Kiyoshi , Kosugi Hiroshi , Uda Hisashi , Kawai Mikio
Published: July 2006

A combination of the reaction of dianions of (phenylthio) acetic acid and its homologs with epoxides, the conjugate addition reaction of 3-phenylthio-2-(5H)-furanones with carbanion species, and the α-alkylation reaction of α-phenylthio-γ-butyrolactones is shown to provide a general method for the synthesis of a variety of substituted α-phenylthio-γ-butyrolactones. Oxidation of these α-phenylthiolactones to the corresponding sulfoxides, followed by pyrolysis furnishes all the types of substituted (3-, 4-, and 5-mono-; 3,4-, 3,5- 4,5-, and 5,5-di-; 3,4,5-tri-) 2(5H)-furanones in good overall yields.
A Macrocyclic Enzyme Model System. Catalytic Properties of 10-Amino-[20]paracyclophane in the Deacylation of p-Nitrophenyl Carboxylates
Authors: Murakami Yukito , Sunamoto Junzo , Kondo Hiroki , Okamoto Hiroshi
Published: July 2006

The catalytic efficiency of 10-amino[20]paracyclophane in the deacylation of p-nitrophenyl carboxylates was investigated in 10.9 or 20.8% (v/v) aqueous ethanol at μ=0.10 (KCl). The present catalyst exhibited marked catalytic effects not only in the free amine but in the ammonium form. The observed saturation-type kinetics is consistent with a reaction mechanism which involves pre-equilibrium complexation between the aminoparacyclophane and the substrate at a 1 : 1 molar ratio, followed by pseudo-intramolecular catalysis effected by the amino group of the macrocycle. Studies on the inhibition effect by 1-dodecanol and the modification of the catalyst by 2,4-dinitrofluorobenzene confirmed the effective binding ability of the present paracyclophane toward hydrophobic substrates. The free amine form of the catalyst acted as an effective nucleophile to give the acylated aminoparacyclophane as confirmed by the product analysis. On the other hand, the protonated amine form also enhanced the ester degradation, retaining a turnover behavior. On the basis of the kinetic solvent isotope effect and the exceedingly minor kinetic effect of [10-oxo[20]paracyclophan-22(23)-ylmethyl]trimethylammonium chloride in the ester degradation in the neutral pH region, a plausible reaction mechanism has been discussed.
Emission Spectra of Phenol, Anisole, and Phenetole by Controlled Electron Impact
Authors: Tsuji Masaharu , Ogawa Teiichiro , Nishimura Yukio , Ishibashi Nobuhiko
Published: July 2006

Upon the impact of an electron beam (100–450 eV) on PhOH, PhOCH3, PhOC2H5, PhCOCH3, and (Ph)2CO at low pressures, the S1 emission of the parent molecule (not from PhCOCH3 and (Ph)2CO) and the photo-emissions from such fragments as H, CH, CO, CO+, and OH were observed in the 200–520 nm region. It was concluded that the S1 emission of the parent molecule originates through both the S0→S1 and S0→S2 (cascade)→S1 excitation processes and that the direct excitation into the lower vibronic levels of S1 is responsible for the appearance of the vibrational structures. Most excited species including CO+(A) from PhOH were confirmed to be primarily produced; however, CO+(A) from PhOCH3, PhOC2H5, and PhCOCH3, and CO(b) from PhCOCH3 were found to be produced competitively through one-electron and two-electron excitation processes in relation to the intensity measurements. The relative contribution of the two-electron excitation process in producing CO+(A) increased with a larger substituent, and it was larger than that for CO(b) in PhCOCH3.
The Formation of VOSO4 on the Surface of V2O5 in the Oxidation of SO2 as Studied by ESR
Authors: Kera Yoshiya , Kuwata Keiji
Published: July 2006

To obtain information on the arrangements of the VOSO4 phase in the surface layer of the V2O5 single crystal, the angular dependencies of an asymmetric ESR spectrum which has been found in the crystal under the conditions of SO2 oxidation and assigned to the VOSO4 phase were examined in detail. Two types of the angular dependency of the spectrum on the static magnetic field were clearly differentiated from each other. In the main spectrum, the direction of g⁄⁄ was completely consistent with the b-axis of the V2O5 crystal, while, on the other hand, in the minor spectrum, it took rather random orientations. From comparisons of the crystal structures between V2O5 and VOSO4, it was deduced, preliminarily, that the α-VOSO4 phase with a layer structure, was regularly aligned along the layer of the V2O5 lattice and that the β-VOSO4 phase without a layer structure took a relatively random orientation to the lattice.
Preparation of Vitamin E Using Cation Exchange Resin Complexes of Metal Ions
Authors: Tachibana Yoji
Published: July 2006

A series of cation exchange resin complexes of metal ions were prepared. These resins are effective catalysts for the preparation of vitamin E and were recycled for use several times with little activity loss. The effect of solvents and metal ions on the reaction is discussed.
Asymmetric Shape of Charge-transfer Absorption in Crystalline Ion Radical Salts
Authors: Iida Yôichi
Published: July 2006

Using the one-dimensional Hubbard model, we proposed an asymmetric band shape for the charge-transfer transition between ion radicals in crystalline ion radical salts. The charge-transfer band of the anion radical salts derived from 2,3-dicyano-p-benzoquinone was explained in terms of such a model.
13C-NMR-Spektren von mono- und disubstituierten Cyclohexenen
Authors: Nakagawa Kiyoshi , Sawai Michimasa , Ishii Yasutaka , Ogawa Masaya
Published: July 2006

13C-NMR-Spektren von mono- und disubstituierten Cyclohexenen werden vorgelegt. Für die 13C-chemischen Verschiebungen von disubstituierten Cyclohexenen gelten gute Additivitäten, sofern nicht sterische Wechselwirkungen auftreten und daraus einige Gesetzmässigkeiten abgeleitet werden können, die in der Konfigurations- und Konformationsanalyse von Bedeutung sind.