bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of Demycarosyl Leucomycin A3 Hydrobromide
Authors: Hiramatsu Mikio , Furusaki Akio , Noda Toshiharu , Naya Keizo , Tomiie Yujiro , Nitta Isamu , Watanabe Tetsuo , Take Teruo , Abe Jinnosuke , Omura Satoshi , Hata Toju 
Published: July 2006

Abstract
The stereochemically-complete molecular structure of demycarosyl leucomycin A3, C30H49-NO11, has been determined by means of an X-ray crystal analysis of its hydrobromide. The crystals of the hydrobromide are orthorhombic with four chemical units in a unit cell with the dimensions of a=19.52±0.03, b=20.63±0.03, and c=9.28±0.03 Å. The space group is P212121. As a result of the present study, it has been found that the crystals contain about 0.6 mole of ethanol per mole of the hydrobromide as alcohol of crystallization. The intensity data were obtained from equi-inclination integrating Weissenberg photographs taken with CuKα radiation around the b and c axes. The structure was elucidated by means of the minimum function, least-squares, and Fourier methods. The atomic coordinates obtained were refined by the block-diagonal least-squares method, anisotropic thermal motion being assumed for only the bromine atom. The final R factor is 14.6%. The molecular structure thus obtained corresponds exactly to that proposed in 1967 by Hata et al. on the chemical evidence, considering the allylic rearrangement in the hydrolysis of leucomycin A3 with dilute hydrochloric acid. The conjugated diene system in the macro ring has the trans-trans configuration. The sugar component, mycaminose, forms a β-glycosidic linkage with the lactone ring.
Crystal Structure of Fukinolidol Di-Bromoacetate
Authors: Katayama Chuji , Furusaki Akio , Nitta Isamu , Hayashi Mitsuo , Naya Keizo 
Published: July 2006

Abstract
Fukinolidol di-bromoacetate, C19H24O6Br2, is a derivative of the new sesquiterpenoids isolated from the flower stalks of wild butterburs. The crystal of this derivative is monoclinic, with two molecules in a unit cell with dimensions of a=17.13, b=8.21, c=7.59 Å, and β=98.8°, and with the space group P21. The structure was elucidated by the heavy-atom method, and the absolute configuration was determined by the application of the anomalous dispersion effect of bromine. The atomic parameters were refined by the least-squares method, using a block-diagonal approximation. The structure thus obtained is the same as that shown by the organic chemical investigation which was carried out parallel with the present X-ray analysis. The molecule has a novel bicyclononane structure with a cis-fused system of a five-membered and a six-membered ring; it also has a spiro γ-lactone ring connected to the former ring. The lactone ring is almost planar, and the other five-membered ring takes a typical envelope conformation, while the six-membered ring is of the chair form.
Effect of Some Metal Oxides on the Specific Resistivities of Magnesium Oxide
Authors: Uehara Akira , Kyuno Eishin , Tsuchiya Ryokichi 
Published: July 2006

Abstract
The specific resistivities of magnesium oxide prepared by igniting magnesium hydroxide at about 1700°C were investigated in the temperature range 200–1200°C. The magnesium oxide was found to have a p-type character by the thermoelectric power method. Ignition at 1000°C in an oxygen stream brought about a small increase in specific resistivities, whereas ignition in a vacuum of 10−3 mmHg caused no appreciable change. The sample including univalent-metal oxides such as Na2O or Li2O showed a distinct decrease in specific resistivities and was converted from a p-type to an n-type semiconductor. Addition of tervalent-metal oxides such as γ-alumina or B2O3 to the magnesium oxide, however, raised the resistivities but gave no change in type.
Structure and Intramolecular Motions in Bicyclo[2.2.2]octane as Studied by Gas Electron Diffraction
Authors: Yokozeki Akimichi , Kuchitsu Kozo , Morino Yonezo 
Published: July 2006

Abstract
A least-squares analysis of the electron-diffraction intensities for bicyclo[2.2.2]octane in gas phase measured at 28°C has given the following structural parameters: rg(C–C) (average)=1.542±0.004Å, rg(C–H) (average)=1.107±0.009Å, rg(C1–C2)=1.538±0.015Å, rg(C2–C3)=1.552±0.029Å, ∠C1–C2–C3=109.7°±0.7°, and ∠H–C–H=110·1°±5·6°, where the uncertainties represent estimated limits of error. The potential function for the twisting motion around the D3h symmetry axis is found to have a broad minimum; in terms of the dihedral angle of torsion about the C2–C3 axis, φ, the potential has an rms angle of 12.0°±1.5° and a “classical turning point” of 21.5°±0.5° (7.2° and 12.8°, respectively, in terms of the dihedral angle of twist, τ). Best fit to the observed intensities has been achieved when a quartic function, V(φ)=k2φ2+k4φ4 with k2=−4.0 kcal/mol and k4=54.2 kcal/mol, is assumed. The potential function probably has a hump of the order of 100 cal/mol at the D3h conformation. Hence, this molecule may be regarded as having a “quasi-D3h structure”. The above features are consistent with those for the derivatives of this molecule in crystal phase studied by Dunitz and Ermer by X-ray diffraction, and also with semiempirical estimates based on the calculations of the intramolecular strain energy.
Polarography of Halides in Dimethylformamide. IV. The Stability Constants of the Halo Complexes of Mercury (II)
Authors: Matsui Yoshihisa , Date Yoshio 
Published: July 2006

Abstract
The overall stability constants (β) of mercuric halide and the tri- and tetrahalogenomercurate ions in dimethylformamide containing 0.1 m tetraethylammonium perchlorate were evaluated by the polarographic method at 25°C. The values of log β obtained were: 24.16 for HgCl2, 31.23 for HgCl3−, 34.57 for HgCl42−, 24.17 for HgBr2, 31.62 for HgBr3−, 34.73 for HgBr42−, 25.93 for HgI2, 33.34 for HgI3−, and 36.02 for HgI42−.
The Syntheses and Properties of the Complexes of Boron with Ethylenediaminetetraacetic Acid and Its Analogs
Authors: Nakatani Mitsuhisa , Takahashi Yoshiaki , Ouchi Akira , Watanuki Kunihiko 
Published: July 2006

Abstract
Two compounds of boron with ethylenediaminetetraacetic acid, H6EDTA(BF4)2 and H4EDTA-(BF3)2, as well as complexes with cyclohexanediaminetetraacetic acid and nitrilotriacetic acid, have been synthesized. Their properties, including their infrared and ultraviolet spectroscopic data, have been investigated and discussed.
On the Polarographic Limiting Current of Solubilized Dye in Nonionic Surfactant Solutions
Authors: Hayano Shigeo , Shinozuka Noriko 
Published: July 2006

Abstract
The nature of the limiting current of the reduction of solubilized dye with nonionic surfactants on a mercury-drop electrode was examined. The solution of anthraquinone derivatives solubilized in an aqueous solution of a nonionic surfactant showed a proportionality of the limiting current to the dye concentration. The linear dependence of the current on the square-root of the mercury-column height, the solpe of the log-plot, and the i-t curves indicated the limiting current to be diffusion-controlled. From the i-t curve measurements, the acceleration of the instantaneous current at the end of the mercury-drop growth was observed with the polyoxyethylene nonylphenylether and Triton X-100. This can be interpreted in relation to the reorientation of the surfactant molecules.
Synthesis of 1,3-Thiazine Derivatives from 2-Iminocyclo-pentanedithiocarboxylic Acid
Authors: Muraoka Motomu , Yokoyama Masataka , Yamamoto Kiyoko , Takeshima Tatsuo 
Published: July 2006

Abstract
Several new 3-substituted and 3,3-disubstituted-1,3,4,5,6,7-hexahydro-1-thioxocyclopenta[d]-[1,3]thiazines were obtained by the reactions of 2-iminocyclopentanedithiocarboxylic acid with some aldehydes and ketones. Some intermediate compounds in these reactions such as 2-amino-2-[2-(piperonylidenamino)-1-cyclopenten-1-yl]thiocarbonylthiocyclopentanedithiocarboxylic acid, 2-amino-2-[2-(vanillylidenamino)-1-cyclopenten-1-yl]thiocarbonylthiocyclopentanedithiocarboxylic acid, and 2-amino-2-[2-(4-methoxybenzylidenamino)-1-cyclopenten-1-yl]thiocarbonylthiocyclopentanedithiocarboxylic acid could be isolated.
Geometric Configurations of α-Cyano-β-methyl-β-alkylglycidic Esters
Authors: Igarashi Minoru , Akano Makiko , Fujimoto Akira , Midorikawa Hiroshi 
Published: July 2006

Abstract
α-Cyanoglycidic ester derivatives have been prepared from alkylidenecyanoacetic esters with hydrogen peroxide. The NMR technique has been applied to the study of the geometric configurations of the stereoisomeric mixture of the glycidic esters. It has been found that the β-methyl protons cis to the ester group respond at a higher field than do the trans protons.
The Preparation of α-Amino-α-benzylmercaptopropionic Acid Derivatives
Authors: Kaneda Akira , Sudo Rokuro 
Published: July 2006

Abstract
The preparation of N-acyl derivatives of α-amino-α-benzylmercaptopropionic acid was investigated. It is described that pyruvic acid was treated with amides to afford N-acyl-α-amino-α-hydroxypropionic acids, which were then substituted into N-acyl-α-amino-α-benzylmercaptopropionic acids. In another experiment, Steglich’s method was improved in order to afford three N-acyl derivatives of α-amino-α-benzylmercaptopropionic acid in a better yield.
The Characterization of Malloprenol and Its Ester with Linolenic Acid Isolated from the Leaves of Mallotus japonicus
Authors: Noda Toshiharu , Take Teruo , Watanabe Tetsuo , Abe Jinnosuke 
Published: July 2006

Abstract
An isoprenoid alcohol (I) and the ester with linolenic acid (II) isolated from Mallotus japonicus of Euphorbiaceae were investigated. The trivial name “mallophenol” was proposed to describe the prenol (I). Nuclear magnetic resonence studies showed that the prenol contained one trans and six cis internal isoprene residues, and a cis ‘OH-terminal’ isoprene residue.
The Catalytic Dehydrogenation, Dehydroxylation and Dehydroxymethylation of Benzyl Alcohol. I. The Scope and the Kinetic Study
Authors: Ishige Masayoshi , Sakai Koji , Kawai Masatoshi , Hata Kazuo 
Published: July 2006

Abstract
Benzyl alcohol was dehydrogenated to benzaldehyde when it was heated in the presence of various metal catalysts. It was found that the dehydrogenation was accompanied by a reductive dehydroxylation and dehydroxymethylation which led to the production of toluene and benzene respectively. The compositions of the products, which mainly consisted of benzaldehyde, toluene, and benzene, were greatly affected by the chemical nature of the catalysts used. The results of the reactions in a sealed tube or in an authoclave suggested that a pseudo-equilibrium between benzyl alcohol and benzaldehyde was attained during the reaction in a closed system. The formation of CO2, CH4, and other hydrocarbons as gaseous products was also observed. From these results, the catalytic dehydrogenation, dehydroxylation, and dehydroxymethylation were assumed to proceed competitively via a certain metal benzyl complex which is formed as an adsorbed transition complex upon the catalyst metal.
The Hydroformylation of Nitroalkenes with Rhodium Carbonyl
Authors: Takesada Masahiko , Wakamatsu Hachiro 
Published: July 2006

Abstract
The hydroformylation of butenes in nitrobenzene or nitroethane gives C5-aldehydes in an excellent yield in the presence of tetrarhodium dodecarbonyl, but in only a poor yield in the presence of dicobalt octacarbonyl. Under hydroformylation conditions, nitrobenzene is hydrogenated to aniline above 150°C with rhodium carbonyl and at 125°C with cobalt carbonyl. The hydroformylation of nitroalkenes with rhodium carbonyl is described. 4-Nitrostyrene gives isomeric (4-nitrophenyl)-propionaldehydes in a 96% yield. 3-Nitropropene-1 gives C4-nitroaldehydes, mostly 2-methyl-3-nitropropionaldehyde, in a 96% yield. However, no reaction of nitroethylene occurred below 140°C.
Studies of Peptide Antibiotics. XX. Synthesis of Tyrocidine B
Authors: Kuromizu Kenji , Izumiya Nobuo 
Published: July 2006

Abstract
A cyclic decapeptide, cyclo-(l-Trp-d-Phe-l-Asn-l-Gln-l-Tyr-l-Val-l-Orn-l-Leu-d-Phe-l-Pro-) (XVIII), having the amino acid sequence of natural tyrocidine B has been synthesized, p-Methoxybenzyloxycarbonyl-Trp-d-Phe-OH was transformed into an acyldipeptide hydroxysuccinimide ester by reagents of hydroxysuccinimide-dicyclohexylcarbodiimide, and the acyldipeptide ester obtained was coupled with a neutral octapeptide. An acyldecapeptide acid thus obtained was subjected to the cyclization reaction. The antibacterial activity of the synthetic product (XVIII) toward Gram positive microorganisms is found to be nearly the same as that of synthetic tyrocidine A, indicating that the l-phenylalanine residue in tyrocidine A can be replaced by l-tryptophan without causing decrease in activity.
Preparation of 1,4-Cycloalkanediones by Hypoiodite Oxidation of Cycloalkanols
Authors: Mori Takasi , Matsui Kiyohide , Nozaki Hitosi 
Published: July 2006

Abstract
Lead tetraacetate oxidation of 11, 12 and 13-membered cycloalkanols gives improved yields of 2,5-polymethylenetetrahydrofurans II in the presence of iodine. Oxidative cleavage of II furnishes 1,4-cycloalkanediones VII.
Dielectric Relaxation and Molecular Structure. II Dielectric Relaxation in Dibutyl Ether, Diphenyl Ether and Benzophenone in Various Nonpolar Solvents
Authors: Vij J T , Srivastava K K 
Published: July 2006

Abstract
Measurements of dielectric constant and loss have been made at 1 Mc and 9.44 GHz for dibutyl ether and benzophenone in various solvents, e.g., n-heptane, benzene, cyclohexane, carbon tetrachloride, decalin and Nujol. Whereas, diphenyl ether has only been studied in benzene and cyclohexane. The values of relaxation time and distribution parameter have been determined by using Cole-Cole’s equation in terms of the so-called slopes, a0, a′, a″ and a∞. The relaxation time values show a regular increase with the increase in viscosity of the medium both for dibutyl ether and benzophenone. The observations seem to suggest that dibutyl ether relaxes both by molecular and intramolecular mechanisms. The dipole moments in various solvents have also been calculated.
Studies of Photochemical Reactions Using Organic Photosensitizers. I. Benzene-Photosensitized Decomposition of Nitrous Oxide
Authors: Yamashita Shigeru , Adachi Kin-ichi , Hayakawa Teruo 
Published: July 2006

Abstract
Benzene-photosensitized decomposition of nitrous oxide has been studied in a mercury-free reaction system. 2537 Å line of low-pressure mercury lamp was absorbed by benzene and the excitation energy of benzene was transferred to nitrous oxide by triplet-triplet energy transfer mechanism. Only N–O bond rupture of nitrous oxide has been observed, which is reasonable from energetic view point. The decomposition yield of the excited triplet state of nitrous oxide was estimated to be 15% and the triplet state seems to be less than 84 kcal/mol above the ground state.
The Reactions of Propylene-1,3,3,3-d4 Photosenitized by Hg(3P1), Cd(3P1), and Benzene-h6 and -d6
Authors: Hirokami Shun-ichi , Sato Shin 
Published: July 2006

Abstract
A comparative study has been made of the reactions of cis- and trans-propylene-1,3,3,3-d4 photosensitized by benzene-h6 and -d6 and by Hg(3P1) at room temperature and by Cd(3P1) at 275°C. The main reaction observed in every photosensitization was a cis-trans isomerization; no isomerization to propylene-2,3,3,3-d4 was observed under the conditions employed. This is in marked contrast to the isomerization of ethylene-d2. The ratio of cis- to trans-propylene-1,3,3,3-d4 after prolonged irradiation was unity. The decomposition observed in the mercury photosensitization was also studied in detail; its quantum yield was less than one-tenth that of the cis-trans isomerization. The material balance between the decrease in the reactant and the amount of the products was well preserved, but the energy balance between the absorbed photons and the quantum yield of products was not preserved at pressures below 150 Torr. A possible mechanism is discussed.
Effect of Halogenation on Intramolecular Energy Transfer in Rare Earth Chelates
Authors: Morita Makoto , Shionoya Shigeo 
Published: July 2006

Abstract
Using tris-dibenzoylmethanates of terbium(III) and other rare earths(III) we investigated the effect of halogenation of the central hydrogen of a 1,3-diketonate ligand on the luminescence properties of these chelates in rigid media. As a result of halogenation, all chelates display blue shift of the ligand phosphorescence, the intensity of the rare earth emission IRE relative to that of the phosphorescence Iph is markedly decreased in the order of H→Cl→Br, and the lifetime of the phosphorescence τph decreases in the same order. These facts provide the evidence that the intramolecular energy transfer takes place via the triplet state of the ligand. In halogenated and nonhalogenated terbium chelates the ratio of the probability of energy transfer Pt estimated from the quantity IRE⁄Iphτph to the overlap integral S between the phosphorescence spectrum and the terbium absorption spectrum is found to be roughly constant. These results lead us to the conclusion that intramolecular energy transfer is governed by the resonance mechanism due to exchange interaction.
Cyclic Diacylcarbene Generated from Iodonium Ylides and Diazodiketones
Authors: Hayasi Yosio , Okada Taiiti , Kawanisi Mituyosi 
Published: July 2006

Abstract
The preparative method of iodonium ylides, Ph–\overset⊕I–\overset\ominusC(COR)(COR′), is improved by condensation of active methylene compounds, H2C(COR)(COR′), with iodosobenzene in the presence of acetic anhydride. Thermal and Cu-catalyzed decomposition of iodonium ylides can be differentiated and both are explained in terms of diacylcarbene intermediate with different multiplicity. For the sake of comparison diazodimedone and related compounds are also decomposed by Cu-catalysis as well as by photochemical reaction. Carbene is also found to be a highly probable intermediate. Throughout these investigations the spin multiplicity of the carbene is discussed on the basis of product distributions. Notably in the presence of homogeneous Cu-catalyst in ethanol, diazodimedone gives an insertion product to O–H bond, 2-ethoxy-3-hydroxy-5,5-dimethyl-2-cyclohexenone (XVII), whereas the iodonium ylides do not give such a compound. The formation of XVII is explained by assuming a ketocarbene-Cu-chelate complex.
The Synthesis of Poly-l-arginine
Authors: Noguchi Junzo , Fujiwara Yukihiko 
Published: July 2006

Abstract
N ω-Tosyl-l-arginine-Na-carboxylic acid anhydride hydrochloride was obtained as a crystal by the reaction of Na-carbobenzyloxy-Nω-tosyl-l-arginine and thionyl chloride. After treatment with silver oxide to remove the hydrochloride, Nω-tosyl-l-arginine-Nω-carboxylic acid anhydride (NCA) was prepared; it was then polymerized to poly-Na-tosyl-l-arginine(M\fallingdotseq16200, n\fallingdotseq52), which was subsequently converted into poly-l-arginine hydrochloride by treating it with hydrogen fluoride and by passing it through a column of the hydrochloride form of the IRA-400 resin.
Lactone Carboxylic Acids. VII. Reaction of Lactone Pyrazolines with Acetic Anhydride. A Preparation of Lignans Skeleton by Thermal Decomposition of Pyrazoline
Authors: Torii Sigeru , Furuta Takuya 
Published: July 2006

Abstract
Cycloaddition of diazomethanes to aconic acids (4 and 14) gave 1-pyrazolines (5, 7 and 15). Thermal decomposition of 7 afforded γ-phenyl-α-benzylaconic acid 8 having a lignans skeleton. By the action of phosphoric acid 5 was converted into 2-pyrazoline 12. The chemical nature of pyrazolines (5 and 12) is discriminated by treatment with acetic anhydride in the presence of p-toluenesulfonic acid. Thus, 1-pyrazoline 5 gave the corresponding derivatives (10, 11 and 13), and 12 gave 13. The thermochemical stability of the pyrazolines (15 and 16) were also studied. A possible mechanism of the formation of 10 and 13 is described.
The Reactions of Sulfur Ylides with Cyclic Carboxyl Compounds and Isocyanates
Authors: Mukaiyama Teruaki , Higo Moriaki , Takei Hisashi 
Published: July 2006

Abstract
It was found that the reactions of dimethyloxosulfoniummethylide (II) with cyclic carboxyl compounds (I), such as lactones, carboxylic anhydrides and imides, gave the corresponding stable oxosulfonium ylides (III). In addition, the reaction of phenyl isocyanate dimer (IX) and dimethylsulfoniummethylide (X) afforded a 1:1 adduct (XI), which, on heating, decomposed to give a ring expansion product (XIV). Hydantoin derivatives (XVII) were also produced by treating dimethylsulfonium-α-methylacylmethylide (XVI) with two moles of isocyanates in dimethyl sulfoxide. On the other hand, when the same reactions were carried out in benzene, XVI reacted with an equimolar amount of isocyanates to give acrylamide derivatives (XVIII) in high yields by the rearrangement of the intermediate sulfoniummethylide (XX).
The Behavior of Indium(III) Complexes in Several Liquid-Liquid Distribution System. I. A Solvent Extraction Study of Indium(III) Complexes in Aqueous Perchlorate Media Containing Several Anionic Ligands
Authors: Hasegawa Yuko 
Published: July 2006

Abstract
The stabilities of the indium(III) complexes in 4 m sodium perchlorate solutions with eight univalent anionic ligands have been studied at 25°C by using a TTA-chelate extraction method and a TBP adduct extraction method. The following conclusions have been reached. The stabilities of the indium(III) halide complexes are larger in this order; Cl−&gt;Br−&gt;I−; on the other hand, those of indium(III) complexes with the halate anions increase in the order: ClO3−&lt;BrO3−&lt;IO3−. The former forms more stable complexes than the latter. Thiocyanate ions form the most stable indium(III) complexes (the first to the fifth complexes), while nitrate ions form the least stable one (only the first complex). The values obtained by the TTA method are almost identical with those obtained by the TBP method. It was also concluded that although the TTA method could be applied to all the systems studied, it is more suitable for the examination of the lower complexes; the TBP method, on the other hand, could be used only for the systems in which an extractable third complex is formed, but it could give more accurate constants for the higher complexes. Thus, only a combination of these two methods can give all the equilibria in a system where many complexes are formed.
Photoemission from Organic Crystal in Vacuum Ultraviolet Region. IV
Authors: Kochi Masakatsu , Harada Yoshiya , Hirooka Tomohiko , Inokuchi Hiroo 
Published: July 2006

Abstract
The quantum yield and the energy distribution of photoelectrons were measured for organic crystals in the vacuum ultraviolet region. A model was presented for the photoemission from organic crystals with a narrow valence band, and a semiempirical power law was derived for the yield near the threshold. The ionization potentials found from the spectral distribution of the quantum yield using this model were as follows: anthracene–5.68 eV, naphthacene—5.43, pentacene—5.04, perylene—5.33, indanthrone—5.17, and tetrathionaphthacene—4.42. The effect of electrons which escape after one inelastic scattering was observed. It was shown how the contribution of once-scattered electrons can be separated in the energy distribution. The threshold for “pair production” was estimated to be nearly equal to the band gap for perylene and a little higher than the band gap for quaterrylene. The fine structures observed both in the yield spectra and in the energy distribution can be accounted for by assuming the existence of additional valence bands.