bluuebunny/crossref_metadata_2025_split huggingface dataset:
12,13-Epoxy-C-nor-D-homosteroids. I. The Synthesis and Stereochemistry of 17α-Acetyl-12,13-epoxyetiojervanes
Authors: Murai Akio , Sasamori Hiroshi , Masamune Tadashi 
Published: July 2006

Abstract
Several 11-substituted 17α-acetyl-12,13-epoxyetiojervanes were prepared from jervine. Jervine was degraded by a known process into (17E)-17-ethyletiojerva-4,12,17(20)-triene-3,l 1-dione, which on epoxidation followed by acid treatment gave 17α-ethyletiojerva-4,12-diene-3,l 1,20-trione as the main product. Acetalization of the carbonyl groups, at C3 and C20 of the triketone and subsequent hydride reduction produced two 11-epimeric alcohols, which on hydrolysis afforded 17α-ethyl-11α-hydroxyetiojerva-4,12-diene-3,20-dione and its 11β-hydroxy epimer. These alcohols and their acetates were oxidized with perbenzoic acid and/or t-butyl hydroperoxide to give the epoxides. The structure and configuration of these epoxides and the synthetic intermediates were determined on the basis of the chemical and spectral evidence.
The Reaction of Azidotriazines with Pyridines and Triphenylphosphine
Authors: Fujinuma Kenji , Hashida Yoji , Matsui Kohji 
Published: July 2006

Abstract
2-Azido-4,6-dimethoxy-1,3,5-triazine (1a) gave an adduct with pyridine in a molar ratio of 1 : 1. On the contrary, 2-azido-4,6-bis(dimethylamino)-1,3,5-triazine (1b) did not react with pyridine. Similarly, 1a gave an adduct with 3-methylpyridine, whereas in the reactions of 1a with 2-methyl-, 4-methyl-, and 2,6-dimethylpyridines, 2-amino-4,6-dimethoxy-1,3,5-triazine was obtained instead of the adduct. On the other hand, 1a and 1b gave the corresponding triazinyliminophosphoranes with triphenylphosphine.
Syntheses of 5-Hydroxyflavone-Transition Metal Complexes
Authors: Hiraki Katsuma , Onishi Masayoshi , Ikeda Tsuyoshi , Tomioka Kazuko , Obayashi Yayoi 
Published: July 2006

Abstract
New complexes [M(hofl)2(OH2)n] (Hhofl=5-hydroxyflavone; M=Co and Ni, n=2; M=Cu, n=1 and 0) and [M(hofl)3] (M=V and Fe) were synthesized and characterized by IR and electronic absorption spectroscopy. Polynuclear ethoxo(5-hydroxyflavonato)metal(II) complexes of cobalt and copper were also prepared.
Synthesis Using Pyridinium N-Ylides. I. Synthesis and Some Reactions of Substituted 1-(Acetylimino)pyridinium Ylides
Authors: Kakehi Akikazu , Ito Suketaka , Konno Yoshiaki , Maeda Toshiaki 
Published: July 2006

Abstract
Pyridinium N-imines reacted smoothly with diethyl malonate and ethyl cyanoacetate in ethanol at room temperature to give the corresponding 1-(ethoxycarbonylacetylimino)- and 1-(cyanoacetylimino)pyridinium ylides in 59–87% yields. These ylides were converted to 1-(acetylimino)pyridinium ylide derivatives by the treatment with acetic anhydride. The alkaline treatment of the pyridinium salts which were prepared by the alkylation of the N-ylides with alkyl halides, gave the corresponding 3-ethoxycarbonyl- and 3-cyano-1,2-dihydropyrazolo-[1,5-a]pyridin-2-one derivatives in 8–51% yields.
Hydrates of Organic Compounds. III. The Formation of Clathrate-like Hydrates of Tetrabutylammonium Dicarboxylates
Authors: Nakayama Haruo , Watanabe Kazuichi 
Published: July 2006

Abstract
The solid-liquid phase diagrams for the binary mixtures of water with 20 tetrabutylammonium dicarboxylates, [(n-C4H9)4N]2OOC–R–COO (R=methylene chain ranging from 0 to 10 carbon atoms; methylene chain containing substituted groups such as –CH3, –C2H5, –NH2, and –OH; and –C6H4– (three phthalate isomers)), have been investigated to see the effect of dicarboxylate anions on the formation of clathrate-like hydrates. It has been found that, with only the one exception of the dodecanedioate, all the other salts form hydrates which have large hydration numbers. Judging from these large hydration numbers, they are believed to be clathrate-like hydrates. From the relationship between the hydration numbers and the melting points, these hydrates can be classified into three groups at least. All the hydrates other than those of oxalate and of terephthalate are newly found in this study.
Optical and Magnetic Properties of Solid Anion Radical Salts Derived from Halogen-Substituted p-Benzoquinones
Authors: Iida Yôichi 
Published: July 2006

Abstract
Crystalline anion radical salts derived from halogen-substituted p-benzoquinones are known to show charge-transfer transition between anion radicals in the low-energy region and to possess antiferromagnetic spin exchange interaction between the anion radicals. Using Hubbard Hamiltonian, the optical and magnetic properties of Na+ p-Chloranil\ewdot were explained in terms of a dimer model, while those of K+ p-Chloranil\ewdot and K+ p-Bromanil\ewdot, in terms of an infinite non-alternant linear chain model.
Absorption and Circular Dichroism Spectra of Cobalt(III) Complexes Containing N,N-Dimethylethylenediamine
Authors: Akamatsu Keiji , Shimura Yoichi 
Published: July 2006

Abstract
Nine new cobalt(III) complexes containing N,N-dimethylethylenediamine are prepared. The geometrical configurations of isomers are assigned on the basis of their visible and ultraviolet absorption spectra, proton magnetic resonance spectra, and the optical resolution of the chiral isomers. The absorption and circular dichroism spectra are discussed in comparison with those of the corresponding complexes containing ethylenediamine, N-methylethylenediamine, N,N′-dimethylethylenediamine, or tris-2-(aminoethyl)amine.
Synthesis of 1,4-Dithiafulvenes and 1,4-Dithiafulvalenes by Carbonyl Olefination Using 2-Dimethoxyphosphinyl-1,3-benzodithiole
Authors: Akiba Kin-ya , Ishikawa Kiyofumi , Inamoto Naoki 
Published: July 2006

Abstract
The reactions of 1,3-dithiolylium salts with tertiary phosphines and trialkyl phosphites in dry acetonitrile gave the corresponding phosphonium salts and the phosphonates respectively in high yields. Both 2-triphenylphosphonio-1,3-benzodithiole tetrafluoroborate and 2-dimethoxyphosphinyl-1,3-benzodithiole were deprotonated with butyllithium in THF at −78 °C and the resulting phosphorane (A) and the phosphonate carbanion (B) reacted with a variety of carbonyl compounds to give 1,4-benzodithiafulvenes in 74–98% yields. Moreover, B reacted with conjugated cyclic ketones (5) such as dibenzo[a,d]cyclohepten-5-one, 10H-9-thiaanthracen-10-one, 9-alkyl-9,10-dihydro-9-azaanthracen-10-one, 9-fluorenone, and so on to give 1,4-benzodithiafulvalenes (6) in 73–96% yields. The UV spectral data of 6 were discussed in comparison with those of 5.
Variation of Transport Properties as Functions of Temperature and Composition in Glass-forming Melts — An Isoenergic Equation
Authors: Islam Nurul , Kumar Satendra , Singh Kunwar Pal 
Published: July 2006

Abstract
Measurements of density, ρ, viscosity, η, and electrical conductance, Λ, in glass-forming molten mixtures of manganese(II) chloride-tetrabutylammonium bromide were made as functions of temperature and composition. The non-Arrhenius temperature dependence of transport properties has been discussed in terms of equations based on the free-volume model. Composition dependence of viscosities has been explained satisfactorily through a parabolic equation, η=p+qN+rN2+sN3, where p, q, r, and s are the empirical parameters and N is the mole fraction of the solute. The minimum in the viscosity isotherms has been observed at N=−q⁄2r. A better applicability of isoenergic equation, Y(=φorΛ)=(A0Y−Q1YN)c−1⁄2(T0(0)+(Q2N)−1⁄2exp[−k1Y⁄(T0(0)+Q2N)(c−1)] over an isothermal equation (both based upon free volume model) in explaining the transport process in all the glass-forming melts has been emphasized.
The Use of Zinc/Silver Couple in the Cyclocoupling Reaction of Polybromo Ketones and Furan
Authors: Sato Tsuneo , Noyori Ryoji 
Published: July 2006

Abstract
The title 3+4→7 reaction, followed by Zn/Cu couple reduction in methanol, affords 8-oxabicyclo[3.2.1]oct-6-en-3-ones in satisfactory yields.
An Upper Limit to the Excited Electron-Cation Recombination Lifetimes of Trapped Electrons in Ethanol and 2-Methyl-tetrahydrofuran Glasses at 4 and 77 K
Authors: Ogasawara Masaaki , Kevan Larry 
Published: July 2006

Abstract
N,N,N′,N′-Tetramethyl-p-phenylenediamine (TMPD) fluorescence lifetimes in 2-methyltetrahydrofuran (MTHF) glass at 77 K (13.5 ns) and in ethanol glass at 77 K (12.3 ns) and 4 K (11.5 ns) were measured using 347 nm excitation from a frequency doubled ruby laser. Trapped electrons and TMPD+ were generated in these matrices by photoionization and the recombination fluorescence stimulated by 694 nm laser light was found, within an experimental limit of 1 ns, to occur with the same lifetime as the directly excited fluorescence. A convolution analysis indicates that the electron-cation recombination lifetimes are ≤1 ns in all these matrices at the temperatures given. It is also suggested that a lower limit for the electron mobility of 0.005 cm2 V−1 s−1 is implied by these data.
The “Overcondensation” of Phosphate Ions and the Formation of Conjugate Metal Oxide upon the Thermal Dehydration-condensation of Hydrogenorthophosphates
Authors: Kawazoe Hiroshi , Ametani Kazuo , Imai Masahiko , Kanazawa Takafumi 
Published: July 2006

Abstract
On the thermal reaction of H3PO4 or NH4H2PO4 with metal salts, such as Na2CO3 or Mg(OH)2, the “overcondensation” of the phosphate anions and the conjugate formation of metal oxide were observed. The “overcondensation” was defined as a formation reaction of the phosphate with a larger polymerization degree than that of the product to be expected from the [MO or M2O]/[P2O5] mole ratio of the starting mixtures. The “overcondensed” tetrametaphosphate and the conjugate oxide, magnesium oxide, were detected on the thermal condensation of MgHPO4·3H2O and of a mixture of NH4H2PO4 or H3PO4 and Mg(OH)2. The “overcondensed” tripoly- and trimeta-phosphate were found in the course of the formation reaction of Na pyrophosphate from a mixture of Na2CO3 and NH4H2PO4.
Synthesis, Reactions and Catalytic Properties of Stable Alkoxocopper, Phenoxocopper and Related Copper Complexes Containing Triphenylphosphine Ligands
Authors: Kubota Minoru , Yamamoto Akio 
Published: July 2006

Abstract
A variety of new alkoxocopper and phenoxocopper(I) complexes containing triphenylphosphine ligands have been prepared by the reactions of methylbis(triphenylphosphine)copper(I) etherate (I) with the corresponding alcohols and phenols. The isolated complexes were characterized by elemental analysis, IR and NMR spectroscopy and chemical reactions. The reactions of the alkoxocopper and phenoxocopper complexes with alkyl halides and acyl halides or carboxylic anhydrides yield ethers and carboxylic esters, respectively. The stoichiometric exchange reactions of the alkoxo group in the alkoxocopper complexes with carboxylic esters proceed smoothly and the alkoxocopper complexes were found to act as excellent catalysts for the transesterifications between carboxylic esters and alcohols. The exchange reactions take place also between the alkoxocopper complexes and phenols or thiols producing phenoxocopper or alkylthiocopper complexes with the liberation of alcohols. Amides and nitromethane react with the alkoxocopper complexes releasing alcohols to give N-bonded amidocopper and O-bonded acinitrocopper complexes, respectively. The thermolysis of the alkoxocopper complexes in various solvents were studied and the mechanism and the factors influencing the course of thermolysis discussed.
A Dimeric Structure of Dimethyllead(IV) Complexes with ONO Tridentate Schiff-base Ligands and the Interaction of These Complexes with Donor Solvents
Authors: Majima Tetsuro , Kawasaki Yoshikane 
Published: July 2006

Abstract
From measurements of the molecular weights, dimethyllead(IV) complexes with ONO tridentate Schiff-base ligands, 2-(2-oxidobenzylideneamino)phenolatos, were found to have dimeric six-coordinate structure in CHCl3, in which either one of the two oxygen atoms in the ligands bridges the lead atoms. The 2J(207Pb–CH3) values increase and the δ(Pb–CH3) values shift to a higher magnetic field with an increase in the donor strength of the solvents. Linear relationships between the 2J(207Pb–CH3) and δ(Pb–CH3) values and Hammett’s σ values of the substituents on the Schiff-base ligands were obtained. These results suggest that the complexes form monomerically as a result of coordination with one and/or two solvent molecules in such donor solvents as DMSO and HMPA, and that the 2J(207Pb–CH3) values is dependent mainly on the change in the positive charge on the lead atom: the change in the mean excitation energy, ΔE, in the Fermi contact term.
The Solution Behavior of Thenoyltrifluoroacetone in Alcoholic Solvents
Authors: Shibuya Hidenori , Watarai Hitoshi , Suzuki Nobuo 
Published: July 2006

Abstract
The solution behavior of thenoyltrifluoroacetone (TTA) has been investigated in a series of higher alcohols which are often used in solvent extraction by means of UV and NMR spectrometries. It was experimentally confirmed that TTA exists in the enol and hemiacetal forms in dehydrated alcohol, while in wet alcohol we should also take a hydrate form into consideration. The fractions of the species at equilibrium were determined, and their dependencies on the water concentration and on the solvent properties, i.e., the dielectric constant and the solubility parameter, were examined. The interconversion rate between the enol and hemiacetal forms were also observed as a function of the water concentration.
A New Catalyst for the Low Temperature Oxo Process with the Characteristic of Easy Separation
Authors: Matsuda Akio , Shin Shigemitsu , Nakayama Jun-ichi , Bando Ken-ichiro , Murata Kazuhisa 
Published: July 2006

Abstract
A new type of catalyst, a cobalt carbonyl-complex has been found for homogeneous hydroformylation. The complex has been prepared from Co2(CO)8 and the ethylene glycol diester of 3-(2-pyridyl)propionic acid as a ligand. The catalyst is active even at the low temperature of 50 °C and very low carbon monoxide pressure range of less than 1 kg/cm2. On subsequent cooling it separates from the reaction product. The ligand was prepared by the hydroesterification of 2-vinylpyridine with carbon monoxide and methanol (or ethanol), followed by the trans-esterification with ethylene glycol. The effect of the partial pressures of carbon monoxide and hydrogen on the product composition and on the recovery of the catalyst was examined. The catalytic activity of the new complex is considerably higher than that of Co2(CO)8 at a lower temperature. The selectivity to linear aldehyde in the presence of new complex is significantly higher than in the presence of Co2(CO)8 when the hydrogen to carbon monoxide ratio (H2/CO) in gas phase is high, but this difference in selectivity is small when the above gas ratio is normal. The new complex can be applied as catalyst for removal of carbon monoxide in hydrogen by means of oxo process.
Metal-catalyzed Organic Photoreactions. The Photooxidation of Olefins in the Presence of Uranyl Acetate
Authors: Murayama Eigoro , Sato Tadashi 
Published: July 2006

Abstract
The photooxidation of olefins in pyridine in the presence of uranyl acetate afforded β-hiydroxy hydroperoxides. It was confirmed by spectroscopic studies and isotope-incorporation experiments that (1) the stereochemistry of the hydroxyl and hydroperoxyl groups in the β-hiydroxy hydroperoxides was trans, (2) the hydroxyl group was added to the less substituted carbon of the double bond, and (3) the oxygen atom in the hydroxyl group originated mainly from the water molecule, while the oxygen atoms in the hydroperoxyl group originated mainly from molecular oxygen. From these results, we proposed a reaction scheme of: (i) the formation of the hydroxyl radical from water by uranyl acetate-catalyzed photolysis, (ii) the addition of the hydroxyl radical to the double bond, (iii) the combination of the resulted radical with molecular oxygen, and (iv) the hydrogen abstraction of the peroxyl radical to give the product. The scheme was further supported by the photoreaction of 2-methyl-2-butene with bromotrichloromethane in the presence of uranyl acetate, which afforded 3-bromo-3-methyl-2-butanol as the major product.
A Convenient Synthesis of 2-Substituted 3-Nitro-2H-chromene Derivatives
Authors: Sakakibara Tohru , Koezuka Masaru , Sudoh Rokuro 
Published: July 2006

Abstract
On reaction with salicylaldehyde, ω-nitrostyrene and 4,6-dimethoxy-5-(2-nitrovinyl)pyrimidine gave a mixture of 3-nitro-4-hydroxyflavan and 3-nitro-2-phenyl-2H-chromene or 2-(4,6-dimethoxy-5-pyrimidinyl)-3-nitro-2H-chromene, respectively, whereas 4,6-dichloro-5-(2-nitrovinyl)pyrimidine afforded substitution products: 4-chloro-6-(2-formylphenoxy)-5-(2-nitrovinyl)pyrimidine and 4,6-bis(2-formylphenoxy)-5-(2-nitrovinyl)pyrimidine.
Refractive Indices and Polarizabilities of Several Molten Rare Earth Chlorides
Authors: Mochinaga Junichi , Igarashi Kazuo , Aoki Toshio , Iwadate Yasuhiko 
Published: July 2006

Abstract
Refractive indices of molten LaCl3, PrCl3, NdCl3, DyCl3, and YCl3 were measured by the cylindrical lens method. The measurements were carried out with the lights of four wavelengths, and the refractive indices so obtained were represented by empirical equations as linear functions of temperature. From the data molar refractivities were calculated. The refractive indices at infinite wavelength were calculated by use of Cauchy’s relation for dispersion, and electronic polarizabilities were obtained for the salt molecules in molten state, and also the electronic polarizabilities of La3+, Pr3+, Dy3+, and Y3+ ions in the melts were obtained.
Temperature Programmed Desorption Study of Water Adsorbed on Metal Oxides. I. Anatase and Rutile
Authors: Egashira Makoto , Kawasumi Shohachi , Kagawa Shuichi , Seiyama Tetsuro 
Published: July 2006

Abstract
The adsorbed state of water on TiO2 was studied by temperature programmed desorption (TPD) in the range 0–1000 °C. Pure anatase and rutile samples, the TPD spectra of water from which were not affected by any contaminant, could be obtained by the hydrolysis of titanium oxalate and tetrachloride solutions, respectively. Two desorption peaks were observed for anatase with the peak maxima at 69–127 (I) and 191–256 °C (II), and three for rutile at 32–90 (I), 188–265 (II), and 310–356 °C (III). The sum of adsorbed amounts for peaks II, and III are within a monolayer coverage, that of peak I exceeding it. The enthalpies of adsorption were evaluated to be 36 and 55–69kJ·mol−1 for peaks I and II of anatase, and 36, 64, and 104 kj·mol−1 for peaks I, II, and III of rutile, respectively. From these results, the corresponding adsorbed species of peak I was tentatively assigned to physical adsorption, that of peak II to chemisorption on surface oxygen ion by hydrogen bond, and that of peak III to chemisortpion on Ti4+ by the coordination of oxygen atom of water molecule. The last species may be dissociated into surface OH groups.
Carrier Effect of Reversed Micelle on Imidazole Catalyst
Authors: Kon-no Kijiro , Kitahara Ayao , Fujiwara Masami 
Published: July 2006

Abstract
The reversed micelles of neither didodecyldimethyl ammonium bromide(DDAB) nor sodium 1,4-bis(2-ethylhexyl) 2-sulfonatosuccinate(AOT) catalyse the decomposition of p-nitrophenyl acetate(PNPA) by themselves. However, these reversed micelles increase the action of imidazole in the decomposition of PNPA by solubilizing it. This interesting carrier effect of the reversed micelle on imidazole was investigated in both anhydrous and hydrous systems. The carrier effect of DDAB was greater than that of AOT. This difference was related to the different interaction between imidazole and each of the surfactants. The existence of the different interaction was made clear from the investigation on the change of chemical shift of the H(1) proton of imidazole upon solubilization by the reversed micelle. The mechanism of the decomposition of PNPA was partially explained from NMR measurements. Aminolysis occurred in anhydrous systems and hydrolysis in hydrous systems. Water pooled in the reversed micelle was more effective than bulk water in enhancing the catalytic effect of imidazole.
The Crystal and Molecular Structure of Daphnetin 8-β-d-Glucopyranoside Dihydrate Isolated from Daphne odora
Authors: Ueno Katsuhiko , Saito Norio , Sato Mitsuhiko 
Published: July 2006

Abstract
The crystal structure of daphnetin 8-β-d-glucopyranoside dihydrate has been determined by the X-ray method. The crystal is monoclinic, space group P21, with the lattice parameters a=7.773(1), b=22.478(5), c=4.715(1) Å, β=99.77(2)°, and Z=2. The structure was determined by the direct method and refined by least-squares to a final R of 0.041 for 2690 observed reflexions. The daphnetin moiety is approximately planar, and little effect from glucosylation is observed in the bond lengths and angles, compared with daphnetin itself. The glucopyranoside is in C1 chair conformation, with the ring torsion angles ranging from 48 to 66°. The anomeric C–O bond is twisted by 78.2° against the coumarin plane, which is the largest value in aromatic glycopyranosides so far reported and which is concomitant with a small valence angle, 114.4°, at the oxygen atom linking the coumarin and the glucose group.
X-Ray Diffraction Studies on the Structures of Tetraammine- and Triamminemonochlorozinc(II) Ions in Aqueous Solution
Authors: Yamaguchi Toshio , Ohtaki Hitoshi 
Published: July 2006

Abstract
X-Ray scattering measurements have been carried out on ammoniacal aqueous solutions of zinc(II) chloride at the NH3/Zn mole ratios of 3.8, 5.0, and 6.6. The radial distribution curves show that the tetraamminezinc(II) complex is formed as the main species, the ammonia molecules within the complex being tetrahedrally coordinated to zinc(II) ion at a distance of (2.03±0.02) Å. Analysis of the radial distribution curve obtained for the solution at the NH3/Zn ratio of 3.8 indicates formation of the mixed complex ZnCl(NH3)3+, the Zn–NH3 and Zn–Cl bond lengths being (2.00±0.03) and (2.30±0.03) Å, respectively.
An X-Ray Photoelectron Spectroscopic Study of Dioxime Metal Complexes
Authors: Yoshida Tooru 
Published: July 2006

Abstract
The O(1s) and N(1s) electron-binding energies were measured for the dioxime complexes of several transition metals by means of the X-ray photoelectron spectroscopic method. On the basis of their chemical shifts, the strength of the intramolecular hydrogen bonds and the charge distribution around the nitrogen atoms in the complexes are discussed. Two kinds of oxygen atoms were observed for all the complexes, and their binding energy differences were in the range of 1.3–1.9 eV. This difference was found to decrease with the increase in the strength of the hydrogen bonds. However, only one kind of nitrogen atom was observed for all the compounds except one. The N(1s) chemical shifts were in the range of 0.2–0.8 eV, and were found to increase slightly in the order of CuII&lt;NiII&lt;PdII&lt;PtII.
3β-Angeloyloxy-10β-hydroxy-9β-senecioyloxyfuranoeremophilane and 3β-Angeloyloxy-10β-hydroxyfuranoeremophilane. New Furanoeremophilane Derivatives from Farfugium japonicum Kitamura
Authors: Nagano Hajime , Takahashi Takeyoshi 
Published: July 2006

Abstract
Two new furanoeremophilane derivatives isolated from Farfugium japonicum Kitamura have been shown to be 3β-angeloyloxy-10β-hydroxy-9β-senecioyloxyfuranoeremophilane and 3β-angeloyloxy-10β-hdroxyfuranoeremophilane.
Formation of Dialkyl α-Siloxybenzylphosphonate via 1,2-Anionic Rearrangement of a Silyl Group
Authors: Sekiguchi Akira , Ikeno Masayuki , Ando Wataru 
Published: July 2006

Abstract
The reactions of silyl phenyl ketones with trialkyl phosphites and dialkyl sodiophosphonates gave dialkyl α-siloxybenzylphosphonates in good yields. The mechanism involves the migration of a silyl group from carbon to anionic oxygen. No deoxygenation of silyl ketone with trialkyl phosphite was observed.