bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymorphism and the Structure of Bis(dichloromethylene)succinic Acid as Studied by Chlorine NQR
Authors: Hashimoto Masao , Mano Koichi , Fujino Akira 
Published: July 2006

Abstract
It was found that bis(dichloromethylne)succinic acid (BDCSA) has two crystal forms, the molecule having an s-trans conformation in each form. A frequency drop of about 1 MHz found for BDCSA might be explained in terms of a short intramolecular contact between the chlorine and oxygen atoms.
Electrochemical Reaction of Organoboranes in the Presence of Propenoic Acid Esters. A Convenient Carboxylic Ester Synthesis from Organoboranes
Authors: Takahashi Yuzuru , Yuasa Kazuma , Tokuda Masao , Itoh Mitsuomi , Suzuki Akira 
Published: July 2006

Abstract
Electrolysis of trialkylboranes using two platinum electrodes in the presence of α,β-unsaturated esters in an acetonitrile solution containing tetraalkylammonium halide as a supporting electrolyte, produces the corresponding alkylated carboxylic acid esters in good yields.
The Synthesis of Several Dipivaloylpolymethylbenzenes
Authors: Suzuki Hitomi , Aomori Yasuo , Mishina Tadashi , Hanafusa Terukiyo 
Published: July 2006

Abstract
2,4-Dipivaloyl-1,3,5-trimethylbenzene, 4,6-dipivaloyl-1,2,3,5-tetramethylbenzene, and 3,6-dipivaloyl-1,2,4,5-tetramethylbenzene were prepared by the Friedel-Grafts dipropionylation of the corresponding polymethylbenzenes, followed by the exhaustive methylation of the resulting diketones with potassium t-butoxide and methyl iodide in boiling benzene-t-butyl alcohol. The PMR and IR spectra are reported for these new compounds.
The Sesquiterpenes of Dendropanax trifidus
Authors: Yoshihara Kazuo , Hirose Yoshio 
Published: July 2006

Abstract
The volatile oils of the leaves, cortex and fruits of Dendropanax trifidus were investigated. Germacrene-D is enantiomeric, sesquiterpenes of other series, such as caryophyllene and selinenes, optically corresponding to those in higher plants.
Transformation of o-Nitrobenzenes to Quinolines with Tetracarbonylhydridoferrate
Authors: Watanabe Yoshihisa , Takatsuki Kunihiko , Shim Sang Chul , Mitsudo Take-aki , Takegami Yoshinobu 
Published: July 2006

Abstract
Condensates of o-nitrobenzaldehyde with carbonyl compounds are reduced with tetracarbonylhydridoferrate under mild conditions to give quinolines in good yields.
The Preparation of Isoxazole Derivatives from a Nitro Sugar with Dimethylsulfonium Phenacylide
Authors: Sakakibara Tohru , Sudoh Rokuro 
Published: July 2006

Abstract
The reaction of methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-α-d-erythro-hex-2-enopyranoside or 5-benzoyl (methyl 4,6-O-benzylidene-2,3-dideoxy-α-d-erythro-hexopyranosido)[3,2-c]isoxazoline N-oxide with dimethylsulfonium phenacylide gave 5-benzoyl-3-(1,3-O-benzylidene-d-erythro-glyceryl)-4-isoxazolecarbaldehyde in a fairly good yield.
Racemization during the Synthesis of Histidine-containing Peptides
Authors: Terada Shigeyuki , Kawabata Akira , Mitsuyasu Nobuo , Aoyagi Haruhiko , Izumiya Nobuo 
Published: July 2006

Abstract
A convenient test for racemization using an amino acid analyzer was developed and applied to examine the effects of several im-protecting groups and synthesis of histidyl peptides.
An Additional Discussion of the Micropore-volume Determination of Active Carbon Using Dubinin-Radushkevich Plots
Authors: Tsunoda Ryoichi 
Published: July 2006

Abstract
The validity of the recently presented method for determining the micropore volume (V0) from the distribution curve of the adsorption potential based on the Dubinin-Radushkevich plot is further discussed in terms of the relationship between the V0 and the adsorption volume (Vh) at the beginning of the hysteresis loop on the adsorption isotherm.
The Photoreaction of 1-Cycloalkenyl Phenethyl Ketone
Authors: Tada Masaru , Saiki Hiroshi , Mizutani Hidemi , Miura Kyo 
Published: July 2006

Abstract
The UV irradiation of 1-cyclopentenyl phenethyl ketone in benzene or methanol gave a cyclobutane derivative. The irradiation of 1-cyclohexenyl phenethyl ketone in methanol or in benzene containing either BF3–Et2O or CF3COOH gave a cycloheptanone derivative. The formation of the cycloheptanone derivative requires an acid catalyst.
Depolarized Rayleigh Wings of the Liquids and Solutions of Some Symmetric Top Molecules
Authors: Kamogawa Keiji 
Published: July 2006

Abstract
Spectra of depolarized Rayleigh wings were observed for the liquids and CCl4 solutions of C6H6, CH3CN, and CHCl3. The spectral band shape can be reproduced very well by a Lorentz function for the low frequency wing component and a Gauss function for the far wing component. The functions for neat liquids gave the relaxation times for orientational motion, which support free rotation models. The relaxation times of the solutions were found to be independent of concentration, the integrated intensities showing a linear dependence on concentration. The results for the wing component are in marked contrast to those found for the central component of the spectra. The difference is discussed in terms of dynamical structure of the liquids.
Syntheses and Electronic Spectra of 2,2′-Isopropylidenedi-8-quinolinol, Its Nickel(II), and Copper(II) Chelates
Authors: Yamamoto Yoshinori , Miura Akira , Kawamata Akira , Miura Masayoshi , Takei Shinsuke 
Published: July 2006

Abstract
The title ligand, which contains two 8-quinolinol (oxine) functions in one molecule, and the Ni(II) and Cu(II) chelates have been synthesized and characterized. Visible and ultraviolet spectra of the chelates and the ligand in several solvents have been measured. Square-coordination of the ligand to the metal has been revealed by a comparison of the d-d bands between the chelates and quadridentate Schiff base chelates in the literature. Intraligand transition bands of the title chelates and the solvent effects on the frequency shifts have been compared with those of the ligand, 8-hydroxy-1-methylquinolinium hydroxide, bis(8-quinolinolato)palladium(II), -copper(II), and -nickel(II), and have been discussed.
Syntheses and Properties of Some Trimethylantimony(V) Complexes of Dithiocarbonate Derivatives
Authors: Ouchi Akira , Shimoi Mamoru , Ebina Fujio , Uehiro Takashi , Yoshino Yukichi 
Published: July 2006

Abstract
New stable trimethylantimony(V) complexes of some dithiocarbonate derivatives, (CH3)3SbL2, where HL=secondary amine-N-carbodithioic acid or O-alkyl dithiocarbonic acid, have been synthesized by the metathetical reaction between dibromotrimethylantimony(V) and the alkali salts of ligands. In these compounds, the antimony is kept quinquevalent. The 1H-NMR peak of the methyl protons of all of these compounds appears as a singlet even at −60 °C. Therefore, the most probable structure for these compounds is the trigonal bipyramidal one, where two unidentate dithiocarbonate derivative ligands bond to antimony from the apical directions.
Studies on Mixed Valence Complexes of Platinum and Palladium. II. The Crystal Structures of [Pt(tn)2][PtCl2(tn)2](BF4)4, [Pt(tn)2][PtBr2(tn)2](ClO4)4, and [Pt(tn)2][PtBr2(tn)2](BF4)4
Authors: Matsumoto Naohide , Yamashita Masahiro , Kida Sigeo 
Published: July 2006

Abstract
The crystal structures of Pt(II)–Pt(IV) complexes, [Pt(tn)2][PtCl2(tn)2](BF4)4 (1), [Pt(tn)2][PtBr2(tn)2](ClO4)4 (2), and [Pt(tn)2][PtBr2(tn)2](BF4)4 (3) have been determined by the single-crystal X-ray diffraction method, where tn denotes trimethylenediamine. The crystals of these complexes are isomorphous with one another and the space group is A222 with a=10.790(2), b=13.872(2), c=10.287(1) Å for 1, a=11.003(6), b=13.979(6), c=10.355(4) Å for 2, and a=10.925(3), b=13.862(3), c=10.291(1) Å for 3. The structures were determined by the heavy atom method and refined by the block-diagonal least-squares method to give the disagreement factor 0.082, 0.089, and 0.086 for 1, 2, and 3, respectively. Each crystal comprises infinite PtII…X–PtIV–X… chains running parallel to the a-axis. In the chain, tetragonal bipyramidal [PtIVX2(tn)2]2+ (X=Cl or Br) and square planar [PtII(tn)2]2+ units are stacked alternately. Two of the fluorine or oxygen atoms of the counter anion are hydrogen-bonded to the nitrogen atoms of the ligand, contributing to the formation of an infinite chain.
Vinyl Polymerization. 375. Radical Polymerization of Vinyl Monomer in Water Initiated with Tin Mercaptides and Iron(III) Ion
Authors: Nakamura Yoshiaki , Ouchi Tatsuro , Imoto Minoru 
Published: July 2006

Abstract
The polymerization of the vinyl monomer was carried out in water, using either dimethylbis(ethylthio)tin or triethyl(p-tolylthio)tin as an initiator. The polymerization required the coexistence of the iron(III) ion. The initiating species was concluded to be a thiyl radical. Macromolecular tin mercaptide was much more effective than monomeric tin mercaptide.
A Synthesis of (±)-β-Vetivone and Its Related Spirovetivanes via the Base-catalyzed Spiroannelation of Phenolic Tosylates
Authors: Torii Sigeru , Uneyama Kenji , Okamoto Kaoru 
Published: July 2006

Abstract
(±)-β-Vetivone was synthesized by the base-catalyzed spiroannelation of 2-[2-(4-hydroxy-2-methylphenyl)-ethyl]-3-methyl-3-butenyl p-toluenesulfonate followed by methylation and subsequent isomerization of the side chain double bond. The reactivities of the related tosylates, 4-(4-hydroxy-2-methylphenyl)-2-isopropylbutyl p-toluenesulfonate, 3-hydroxy-2-[2-(4-hydroxy-2-methylphenylethyl]-3-methylbutyl p-toluenesulfonate, and 2,3-epoxy-2-[2-(4-hydroxy-2-methylphenyl)ethyl]-3-methylbutyl p-toluenesulfonate have been discussed.
Synthetic Studies on Pyridomycin. III. Chiral Synthesis of (2R,2S)-(−)-2,3-Dihydroxy-3-methylpentanoic Acid from Sugar Derivative
Authors: Kinoshita Mitsuhiro , Hamazaki Hiroshi , Awamura Masaki 
Published: July 2006

Abstract
The Grignard reaction of 3-O-benzyl-6-deoxy-1,2-O-isopropylidene-α-d-xylo-hexofuranos-5-ulose (5) with ethylmagnesium bromide yielded 3-O-benzyl-6-deoxy-5-C-ethyl-1,2-O-isopropylidene-α-d-glucofuranose (6) as a major product in 91% stereoselectivity. Hydrolysis of 6 followed by successive periodate oxidation and lithium aluminium hydride reduction gave 2-O-benzyl-5-deoxy-4-C-ethyl-d-arabinitol. Selective benzoylation of 9 followed by successive 3,4-O-isopropylidenation, debenzoylation, hydrogenolysis, and two-stage oxidation with periodate-hypoiodite afforded (4R,5S)-(+)-5-ethyl-2,2,5-trimethyl-1,3-dioxolane-4-carboxylic acid (15) in 24.6% overall yield from 5. Hydrolysis of 15 gave (2R,3S)-(−)-2,3-dihydroxy-3-methylpentanoic acid. The acetonide 15 is usefull as a synthon for pyridomycin synthesis.
Thermal Curtius Rearrangement of N-Acyl-S,S-diphenylsulfilimine
Authors: Furukawa Naomichi , Fukumura Mitsuo , Nishio Takehiko , Oae Shigeru 
Published: July 2006

Abstract
Several N-acyl-S,S-arylphenylsulfilimines were prepared and subjected to thermal decomposition. They decomposed readily at 130–190 °C to give isocyanates together with diphenyl sulfide, quantitatively. However, N-tosyl-S,S-diphenylsulfilimine did not decompose even upon heating at 200 °C for 24 h. A kinetic study revealed that the rates of pyrolysis of N-aroyl-S,S-arylphenylsulfilimines (p-Y–C6H4(Ph)S→NCOC6H4–X-p) are nicely correlated with the Hammett σ-values, ρX=−1.2 and ρY=+0.92, respectively, being obtained. The activation enthalpies and entropies were ΔH\eweq=38.7 kcal/mol and ΔS\eweq=6.0 e.u. for Ph2S→NCOPh and ΔH\eweq=32.3 kcal/mol and ΔS\eweq=5.5 e.u. for (Remark: Graphics omitted.), respectively. The rearrangement was accelerated considerably by o-methyl substituent in the aryl group. The effect of solvent on the rate of pyrolysis was small. The results indicate that the pyrolysis of sulfilimine proceeds via a concerted migration of the R group from carbonyl carbon to imino nitrogen similar to the Curtius type rearrangement of acid azide.
Synthesis of 4-Cinnamylidene-2,5-cyclohexadien-1-ones
Authors: Kurosawa Kazu , Hashiba Atsuko , Takahashi Hirobumi 
Published: July 2006

Abstract
Lithium aluminium hydride (LAH) reduction of 4′-hydroxychalcones, followed by dehydration, yielded 4-cinnamylidene-2,5-cyclohexadien-1-ones in 19–42% yields. The LAH reduction of 4′-acetoxychalcones also gave the same products in improved yields.
Coenzyme Models. XIII. Micellar Catalysis of 1,4-Dihydronicotinamide Reduction of Isoalloxazines and Acridinium Ion
Authors: Shinkai Seiji , Ide Toyoko , Manabe Osamu 
Published: July 2006

Abstract
The 1,4-dihydronicotinamide reduction of isoalloxazines and acridinium ion was examined in cationic (CTAB, CPyB), anionic (SDS), and nonionic (POOA, Brij35) micelles. The micellar effect is accounted for by micellar stabilization (or destabilization) of the micelle-bound species.
Photochemical Ethoxycarbonylmethylation of Alkylbenzenes with Ethyl Chloroacetate. MO Calculation for Prediction of Orientation
Authors: Ogata Yoshiro , Hayashi Eizi , Kato Hiroshi 
Published: July 2006

Abstract
Photoreaction of ethyl chloroacetate with cumene gives ethyl cumenylacetates (17.5%) in the ratio o : m : p = 17 : 46 : 37. The same reaction with t-butylbenzene gives ethyl t-butylphenylacetate (23%) in the ratio o : m : p = trace : 65 : 35. Addition of BF3 increases the total yield of the substitution products. Orientations together with those for toluene and anisole in ethoxycarbonylmethylation were discussed in terms of INDO-type MO calculation of the lowest singlet excitation energies.
Liquid-phase Oxidation of Anthracene in Acetic Acid by Copper(II) Chloro Complexes
Authors: Koshitani Jinya , Hiramatsu Masayoshi , Ueno Yoshio , Yoshida Takatoshi 
Published: July 2006

Abstract
Copper(II) chloro complexes contribute to the liquid-phase oxidation of anthracene in acetic acid. Products of the oxidation were anthrone, anthraquinone, 9-acetoxyanthracene, and 9-chloroanthracene.
Kinetic Studies of Photosensitized Oxygenation by Singlet Oxygen in Aqueous Micellar Solutions
Authors: Usui Yoshiharu , Tsukada Michio , Nakamura Hiroko 
Published: July 2006

Abstract
Singlet oxygen produced by the dye-sensitized reaction in an aqueous solution penetrates into the interior of the surfactant micelles of sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium chloride (DTAC), reacting with the solubilized acceptors such as 9,10-dimethylanthracene, 2,5-diphenyloxazole, and 1,3-diphenylisobenzofuran. From the acceptor concentration effect on the photooxygenation quantum yield, the reactivity index (β), the ratio of the rate constant of the spontaneous decay of singlet oxygen to that of the reaction with an acceptor, is obtained in the aqueous micellar solution. It has been shown that the lifetime of singlet oxygen is mainly dependent on the solvent composition in the bulk phase from the kinetic analysis of the mixed solvent effect on the quantum yield in SDS and DTAC micellear solutions and that in a homogeneous solution.
Emission Spectra of Naphthalene Derivatives by Controlled Electron Impact
Authors: Ogawa Teiichiro , Miyamoto Nobuaki , Ishibashi Nobuhiko 
Published: July 2006

Abstract
Naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1-naphthol, 1-naphthylamine, 2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene, and tetralin were excited in a very low pressure by controlled electron beam of 150–400 eV. The molecules, except those with a halogen atom, revealed an intense emission band similar to fluorescence. The band was assigned to the transition from their lowest-excited singlet state to their ground state. It was concluded that the most important process of photoemission is the excitation into a higher excited state in the primary collision and the subsequent non-radiative transfer to the lowest-excited state. The molecules showed photoemission of such excited fragments as H, CH, C2, C4H2+, CN, NH, OH, CO, CO+, HCL+, and HBr+. A two-electron process by way of an intermediate was found to be important for the formation of such fragments as CN from naphthylamine.
The Effect of Σ-Π Interaction on the Electronic Structure of Molecules in the Excited States. II. Oscillator Strength
Authors: Maki Izumi , Kitaura Kazuo , Nishimoto Kichisuke 
Published: July 2006

Abstract
The effect of Σ-Π interaction on the oscillator strength of π-π* transition has been investigated in terms of the configuration interaction method considering all singly excited configurations. It has been found that the transition moment associated with π-π* excitation is modified by σ-electrons. The correction term of the transition moment resulting from the Σ-Π interaction can be expressed by the bond index matrix. The present theory has been applied to the calculation of the oscillator strength of benzene and naphthalene derivatives. Agreement between the calculated values and experimental data is satisfactory. The effect of Σ-Π interaction on the transition moment has been demonstrated pictorially.
A Modified Synthesis of 2,15-Hexadecanedione, a Precursor of Muscone, from a Butadiene Telomer
Authors: Tsuji Jiro , Kaito Mitsumasa , Takahashi Takashi 
Published: July 2006

Abstract
8-Acetoxy-1,6-octadiene was oxidized with PdCl2/CuCl/O2 to give 8-acetoxy-6-octen-2-one. Hydrolysis and hydrogenation of the ketone produced 8-hydroxy-2-octanone, which was converted to the tosylate after protection of the ketone. The tosylate was converted into the iodide and bromide. The bromide was converted into the Grignard reagent, and coupled with the iodide by the catalysis of CuI coordinated by 2,2′-bipyridyl to give 2,15-hexadecanedione.
Syntheses of Polymerizable Aromatic Mannich Bases by Means of Amine Exchange Reaction
Authors: Kamogawa Hiroyoshi , Kubota Kuniaki , Nanasawa Masato 
Published: July 2006

Abstract
Amine exchange reactions between p-vinyl-β-dimethylaminopropiophenone and arylamine hydrochloride provided six novel aromatic Mannich bases bearing a vinyl group which were otherwise hardly accessible. Thus, by refluxingin ethanol-water (1:1),p-vinyl-β-(p-anisidino)-,p-vinyl-β-(p-toluidino)-,p-vinyl-β-(p-hydroxyanilino)-, p-vinyl-β-anilino-, p-vinyl-β-(p-carboxyanilino)-, and p-vinyl-β-(p-nitroanilino)-propiophenones were obtained in 62.0, 55.2, 24.5, 32.0, 47.3, and 29.1% yields, respectively. The Mannich bases thus synthesized underwent ready radical polymerizations to afford the corresponding vinyl polymers, bearing aromatic Mannich base units as pendants.
Reaction of Nitrile Oxides with N-Aryl-S,S-dimethylsuIfimides
Authors: Shiraishi Shinsaku , Shigemoto Tadashi , Ogawa Shojiro 
Published: July 2006

Abstract
Both benzimidazole 3-oxides and 1,2,4-benzoxadiazines were formed in reactions of sterically-stabilized benzonitrile oxides with N-aryl-S,S-dimethylsulfimides, whereas only 1,2,4-benzoxadiazines were produced in reactions of 2,6-unsubstituted benzonitrile oxides. The reactions are thought to proceed via the intermediacy of a nitroso compound formed by the nucleophilic attack of sulfimide on the carbon atom of the nitrile oxide and the subsequent release of dimethyl sulfide. The nitrogen or the oxygen atom of the nitroso group of this intermediate can attack the ortho position of the benzene ring originating from sulfimide to form benzimidazole 3-oxide or 1,2,4-benzoxadiazine, respectively, Conjugation of the nitroso group with the C-aryl group can be attained in s-cis form for the intermediate derived from 2,6-unsubstituted benzonitrile oxide, and thus, exclusive O-attack takes place to afford 1,2,4-benzoxadiazines. On the other hand, conjugation of the nitroso group with the C-aryl group cannot be considered for the intermediate derived from 2,6-disubstituted benzonitrile oxide because of the steric hindrance of the substituents. In this case, the intermediate nitroso compound is either in s-cis or in s-trans form. This causes the formation of both benzimidazole 3-oxide and 1,2,4-benzoxadiazine. Characterization data of benzimidazole 3-oxides are also described.
The Michael Type Alkylation of α,β-Unsaturated Sulfoxide and Reaction of the Resulting α-Sulfinyl Carbanion
Authors: Sugihara Hideki , Tanikaga Rikuhei , Tanaka Kazuhiko , Kaji Aritsune 
Published: July 2006

Abstract
Aryl vinyl sulfoxide was alkylated via the Michael-type addition with lithium dialkylcuprates, and the resulting α-sulfinyl carbanions were reacted with various electrophiles (i.e. aldehydes, ketones, and alkyl halides) to afford a-substituted alkyl sulfoxides.
Absolute Stereochemistry of Cacalol
Authors: Terabe Mahito , Tada Masahiro , Takahashi Takeyoshi 
Published: July 2006

Abstract
Descriptions on the absolute configuration at C-5 of cacalol have been confused. Ozonolysis of cacalol afforded (S)-(+)-2-methylhexanedioic acid. The asymmetric center at C-5 of cacalol, cacalone, and of sesquiterpenes related to these compounds was therefore established to be (S)-configuration.
A Molecular-orbital Calculation of Chemically-interacting Systems. Interaction between Two Radicals. Self-reaction of Peroxyl Radicals
Authors: Minato Tsutomu , Yamabe Shinichi , Fujimoto Hiroshi , Fukui Kenichi 
Published: July 2006

Abstract
The path of the termination reaction of peroxyl radicals (self-reaction) was studied by means of a perturbational method and its reaction mechanism was elucidated theoretically. It was ascertained from this calculation that the self-reaction of tertiary alkylperoxyl radicals yielding a tetroxide does not have a four-centered transition state with four oxygen atoms of the two peroxyl radicals participating, but has a two-centered transition state with only the terminal oxygen atoms. The self-reaction of primary or secondary alkylperoxyl radicals is found to have a six-centered transition state. The self-reaction of acylperoxyl radicals is also shown to have a six-centered transition state. The mechanism of these self-reactions is clarified in terms of the mode of the particular orbital interaction.
Photo-effects of Metal Oxide Electrode. I. Photoelectrochemical Processes on a Silver–Silver Oxide Electrode and the Influence of Ethylene Glycol
Authors: Kunugi Akira , Miyoshi Shuji , Nagaura Shigeo 
Published: July 2006

Abstract
The influence of light excitation on the anodic oxidation of a silver electrode in alkaline solutions has been studied. The experimental results have shown that, in addition to the formation of Ag(II) species by a reaction of Ag(I) species with photo-generated holes, illumination in the Ag2O formation region causes the photogeneration of Ag(I) species at the metal/oxide interface. In the presence of ethylene glycol, the so-called current doubling phenomenon was found. This phenomenon has been interpreted in terms of a mechanism involving a catalytic reaction of the glycol with the photogenerated Ag(II) species, and not by a mechanism involving the oxidation of glycol by the photo-generated holes.