bluuebunny/crossref_metadata_2025 huggingface dataset:
STRUCTURES OF THREE NEW ENT-LONGIPINANE TYPE SESQUITERPENOIDS FROM THE LIVERWORT MARSUPELLA EMARGINATA SUBSP. TUBULOSA
Authors: Matsuo Akihiko , Uto Seiryû , Sakuda Keisuke , Uchio Yasuto , Nakayama Mitsuru , Hayashi Shûichi
Published: July 2006

Three new sesquiterpenoids were isolated from the liverwort Marsupella emarginata subsp. tubulosa. The structures and absolute configurations of the compounds have been shown to be (−)-marsupellone(1), (+)-marsupellol(2) and (+)-acetoxymarsupellone(3), containing an ent-longipinane skeleton, on the basis of chemical and spectral evidence.
PHOTO-INDUCED CYCLODIMERIZATION OF ELECTRON-RICH AROMATIC OLEFINS IN THE PRESENCE OF TRANSITION METAL COMPLEXES
Authors: Mizuno Kazuhiko , Ogawa Jun , Kamura Masafumi , Otsuji Yoshio
Published: July 2006

Irradiation of an acetonitrile solution of phenyl vinyl ether in the presence of various metal complexes[Fe(III) and Mn(II) complexes] gave two cyclodimers. Similar irradiation of 1,1-dimethylindene and 1,1-diphenylethylene afforded the corresponding cyclodimers. In these photodimerization, the metal complexes with ligands such as 2,2′-bipyridine and 1,10-phenanthroline served as catalysts for electron-transfer reaction.
DECOMPOSITION OF POLYCHLORINATED BIPHENYLS (PCB’s) IN A RADIO-FREQUENCY GLOW DISCHARGE PLASMA
Authors: Hiraoka Kenzo , Mitsumori Ken-ichi , Mochizuki Shuji
Published: July 2006

A study was made on the decomposition of PCB’s in a radio-frequency glow discharge plasma. When PCB’s were decomposed in a plasma of oxygen at a few Torr, they were completely decomposed to gaseous products: carbon monoxide, carbon dioxide, water, hydrogen chloride, chlorine, and chlorine dioxide. Hazardous compounds such as phosgene and vinyl chloride were not detected by a GC-MS analysis.
CIRCULAR DICHROISM AND 13C-NMR SPECTRA OF SIX MEMBERED PLATINUM(II) CHELATES CONTAINING OPTICALLY ACTIVE DIAMINES
Authors: Noji Masahide , Okamoto Koji , Kidani Yoshinori
Published: July 2006

The conformations of [Pt(NH3)2(R,R-dppn)]Cl2 and [Pt(NH3)2(R,S-dppn)]Cl2 (dppn=1,3-diphenyl-1,3-propanediamine) were decided to be chair forms on their 13C-NMR spectra. The additive law did not hold among the absolute CD strength of six membered Pt(II) chelates containing (S)-1,3-butanediamine, (S,S)-2,4-pentanediamine and R,R-dppn. In evaluating their absolute CD strength, the vicinal effect of methyl and phenyl groups should be taken into consideration, especially the latter group showed abnormally large increment.
SYNTHESIS AND PROPERTIES OF 1,2-BIS(TRIMETHYLSILYL)TRICYCLO[4.1.0.02,7]HEPT-4-EN-3-ONE. A NOVEL SUBSTITUTED TROPOVALENE
Authors: Sugihara Yoshikazu , Morokoshi Noritsugu , Murata Ichiro
Published: July 2006

1,2-Bis(trimethylsilyl)tricyclo[4.1.0.02,7]hept-4-en-3-one (3) has been synthesized from 4-acetoxy-2-cyclopenten-1-one and bis(trimethylsilyl)acetylene. Photochemical and transition metal promoted isomerizations of 3 are described.
ELECTROCHEMICAL PROPERTIES OF POLYTETRACYANOETHYLENE METAL CHELATE FILMS PREPARED ON METALS BY GAS PHASE REACTION
Authors: Hiratsuka Kazuya , Sasaki Hideo , Toshima Shinobu
Published: July 2006

Current-potential characteristics of iron, copper and nickel chelate films prepared by gas phase reaction of tetracyanoethylene with metals have been measured by cyclic voltammetry. The iron chelate film electrode showed a nearly reversible voltammogram for the reduction of iron(III) ethylenediaminetetraacetate and exhibited electrocatalytic activity for the oxygen reduction.
SEPARATION OF 2-METHYLPENTANE AND 2,2-DIMETHYLBUTANE BY MEANS OF SHAPE-SELECTIVE ADSORPTION INTO MODIFIED H-MORDENITE
Authors: Namba Seitaro , Yoshimura Atsushi , Yashima Tatsuaki
Published: July 2006

A competitive adsorption of 2-methylpentane and 2,2-dimethylbutane into various zeolites were carried out in a 1,3,5-trimethylbenzene solution at 273 K. Partially exchanged H-mordenite by Sr2+ or Ba2+ and a new type zeolite (H-ZSM-5) could adsorb only 2-methylpentane. We succeeded in the complete separation of 2-methylpentane and 2,2-dimethylbutane.
CYCLOPROPANATION OF ELECTRON-DEFICIENT OLEFINS WITH gem-DIBROMIDES CATALYZED BY NICKEL CATALYSTS
Authors: Kanai Hiroyoshi , Hiraki Nobuyuki
Published: July 2006

The cyclopropanation of electron-deficient olefins with gem-dibromides was catalyzed by nickel catalysts. The addition of Lewis acids or sodium iodide and zinc resulted in an increase of the yield.
PHOTO-INDUCED CYCLOADDITIONS OF EPOXYQUINONE TO ALDEHYDES AND KETONES
Authors: Maruyama Kazuhiro , Osuka Atsuhiro
Published: July 2006

Irradiation of a benzene solution of 2,3-dimethyl-2,3-epoxy-2,3-dihydro-1,4-naphthoquinone (1) and an aldehyde gave 1,3-dioxolanes 3 and 4 in high yields. Photolysis of 1 in a ketone gave 1,3-dioxolane 5.
STEREOSPECIFIC ENDO HYDROBORATION OF TRICYCLO[6.2.1.02,6]UNDEC-2(6)-ENE. AN EXAMPLE OF PRODUCT DEVELOPMENT CONTROL IN ADDITION REACTIONS OF BRIDGED POLYCYCLIC COMPOUNDS
Authors: Takaishi Naotake , Inamoto Yoshiaki , Aigami Koji
Published: July 2006

Hydroboration of the title olefin 1 took place under product development control to give exclusively the endo-2-exo-6 isomer 4x of tricyclo[6.2.1.02,6]undecan-exo-3-ol through the diborane attack on the endo side, which was considered to be more hindered on the basis of the formation of the exo-epoxide 8.
THE SYNTHESIS OF 4-ETHOXYINDENO[1,2-d]AZEPINE
Authors: Kimura Masaru , Satake Kyosuke , Morosawa Shiro
Published: July 2006

4-Ethoxyindeno[1,2-d]azepine (8) was prepared by O-ethylation of 4-hydroxyindeno[1,2-d]azepine (6ab) with Et3OBF4 in a 53% yield. 6ab was obtained by bromination of 4-oxo-1,2,3,4-tetrahydroindeno[1,2-d]azepine with NBS, and subsequent dehydrobromination of the corresponding bromo derivative formed in situ on basic alumina in a 10% yield. The NMR and electronic spectra of 8 indicated the presence of a fully conjugated 14-pi ring system in it.
STRUCTURE OF YOMOGIARTEMIN, A NOVEL SESQUITERPENE α-METHYLENE-γ-LACTONE FROM Artemisia feddei
Authors: Koreeda Masato , Matsueda Sumu , Satomi Takehiro , Hirotsu Ken , Clardy Jon
Published: July 2006

A novel diepoxy-guaianolide sesquiterpene α-methylene-γ-lactone, yomogiartemin 1, has been isolated from Artemisia feddei of the Compositae family. The structure was determined by both spectroscopic mehtods and x-ray analysis.
FREE RADICAL FORMATION IN THE MIXED POWDERS OF SACCHARIDES AND METALOXIDES
Authors: Kashiwagi Hiroshi , Yokoi Hideharu , Enomoto Saburo
Published: July 2006

Stable free radical formation was observed in the mixed powders of saccharides and metaloxides. The number of free radicals formed was found to be reduced with an increase in water contents in the powder. Free radicals disappered on kneading the mixtures with water, but they were stable when suspended in benzene. Very little free radical formation was observed in the binary systems containing glucose.
THE PREPARATION OF N1-ALKOXYCARBONYL-N2-(METHYLTHIO)THIOCARBONYLGUANIDINES VIA Δ4-l,2,4-THIADIAZOLINE DERIVATIVES
Authors: Fuchigami Toshio , Nonaka Tsutomu
Published: July 2006

The reaction of potassium methyl cyanoiminodithiocarbonate (1) with N-chlorocarbamates (2) gave 2-alkoxycarbonyl-3-imino-5-methylthio-Δ4-1,2,4-thiadiazolines (3). The reduction of (3) with hydrogen sulfide gave N1- alkoxycarbonyl-N2-(methylthio)thiocarbonylguanidines (4) quantitatively.
ENHANCING AND IMPROVING EFFECTS OF Sn ON Ru–Al2O3 CATALYST ON THE REDUCTION OF NO AND CO IN THE OXIDATIVE ATMOSPHERE
Authors: Masai Mitsuo , Yabashi Masakazu , Kobayashi Hideyo
Published: July 2006

The catalytic activity of Ru–γ–Al2O3 on simultaneous removal of NO and CO in oxidative atmosphere was enhanced by alloying with Sn. The degree of the enhancement was lesser than that observed on Rh–Sn–γ–Al2O3. The weight loss caused by the evaporation of toxic higher oxides of Ru from the catalyst was lowered by alloying with Sn.
ONE HOST-TWO GUESTS COMPLEXATION OF PHOTOSENSITIVE CAPPED CYCLODEXTRIN WITH AMINO ACIDS
Authors: Ueno Akihiko , Saka Rumiko , Osa Tetsuo
Published: July 2006

Azobenzene-capped β-cyclodextrin (I) forms complexes with amino acids according to 1:2 host/guest stoichiometry in which different molar ellipticities are assumed for 1:1 and 1:2 host/guest complexes. The result of the stoichiometry indicates that the guest molecule included first is bound to I much more strongly than the second one.
FACILE SYNTHESIS OF UNSUMMETRICAL SULFIDES USING BIS(2,2,2-TRIFLUOROETHOXY)TRIPHENYLPHOSPHORANE
Authors: Kubota Toshio , Miyashita Satoshi , Kitazume Tomoya , Ishikawa Nobuo
Published: July 2006

Bis (2,2,2-trifluoroethoxy)triphenylphosphorane (1) was found to behave as a potential reagent for the condensation of alcohols with thiols. Using this reagent, a variety of unsymmetrical sulfides were prepared under mild conditions.
31P NMR STUDIES ON THE CONFORMATIONS IN SOLUTION OF PYRROLIDINEPHOSPHINE–RHODIUM COMPLEXES, EFFECTIVE CATALYSTS FOR THE ASYMMETRIC HYDROGENATIONS
Authors: Achiwa Kazuo , Ohga Yoko , Iitaka Yoichi
Published: July 2006

FPPM–, BPPM– and PPPM–Rh+ (COD) complexes have the planar four cordinated structures, whereas PPM–Rh+(COD) complex has the trigonal bipyramidal five cordinated structure. Furthermore, the ratios between the rotational isomers of the complexes resulted from their N-substituent were clarified.
REGIO- AND STEREOCONTROLLED POLYPRENYLATION OF QUINONES. A NEW SYNTHETIC METHOD OF VITAMIN K SERIES
Authors: Naruta Yoshinori , Maruyama Kazuhiro
Published: July 2006

Polyprenyltrimethyltins were prepared in high yields by the coupling reaction of polyprenyl halides (geranyl, nenyl, farnesyl, and phytyl chloride) with trimethyltinlithium with retention of the stereochemistry at Δ2 position. In the presence of BF3·OEt2, coupling of the resulting polyprenyltin reagents with 2-methyl-1,4-naphthoquinone occurred to give vitamin K1 and K2 without any loss of their stereochemistry in the prenyl side chain.
AN EFFICIENT METHOD FOR THE SYNTHESIS OF MIXED DIESTERS OF PHOSPHORIC ACID
Authors: Mukaiyama Teruaki , Morito Naoya , Watanabe Yutaka
Published: July 2006

The reaction of 2-alkyloxybenzoxazoles with bis(p-nitrophenyl) hydrogen phosphate, and subsequent removal of one of two p-nitrophenoxy groups in the resulting alkyl bis(p-nitrophenyl) phosphate gave alkyl p-nitrophenyl phosphates. These were then converted to mixed dialkyl hydrogen phosphates in good overall yields by repetition of the above two-step procedure. The stepwise removal of two p-nitrophenoxy groups was successfully accomplished by the use of tetrabutylammonium acetate under very mild conditions.
PHOTO-INDUCED REARRANGEMENT OF WIDDROL HYPOIODITE
Authors: Takahashi Hajime , Ito Masaaki , Suginome Hiroshi , Masamune Tadashi
Published: July 2006

Hypoiodite of widdrol, a sesquiterpene, underwent a rearrangement to 5, 6,7,8-tetrahydro-2ξ-iodo-2ξ,4aβ,8,8-tetramethyl-8aα-vinylchroman on irradiation. Reflux in acetic acid containing sodium acetate transformed it into several compounds resulting from elimination of hydrogen iodide and reactions with generated iodine.
SYNTHESIS OF β-SILOXYALKYL PHENYL SELENIDES BY THE REACTION OF PHENYL TRIMETHYLSILYL SELENIDE WITH EPOXIDES
Authors: Miyoshi Noritaka , Kondo Kiyoshi , Murai Shinji , Sonoda Noboru
Published: July 2006

The reaction of phenyl trimethylsilyl selenide with epoxides using zinc iodide or n-butyllithium as a catalyst gave β-siloxyalkyl phenyl selenides in good yield.
LABORATORY STUDIES OF HETEROGENEOUS PHOTOCHEMICAL REACTION BETWEEN PROPYLENE AND NITROGEN DIOXIDE OVER ZINC OXIDE
Authors: Ibusuki Takashi
Published: July 2006

The photochemical reaction between C3H6 and NO2 in air over ZnO was investigated in order to elucidate the chemical influences of atmospheric particles on photochemical smog formation. A photocatalytic action of ZnO was demonstrated from the findings: HCN formation, a remarkable increase in C3H6 consumption and CO2 formation rates, and larger values of activation energies for formation of CO2 and CH3CHO than those obtained without ZnO.
A NOVEL OXIDATIVE RING EXPANSION REACTION OF 2-ALKYLIDENE-1,3-DITHIANES INTO 3-ALKYL-1,4-DITHIEPAN-2-ONES WITH Pb(OAc)4
Authors: Hiroi Kunio , Sato Shuko
Published: July 2006

The oxidative ring transformation reaction of 2-alkylidene-1,3-dithianes (1a–e) with Pb(OAc)4 produced 3-alkyl-1,4-dithiepan-2-ones (2a–e) in fairly good yields. The reaction of 2-benzylidene-1,3-dithiane (1f) with Pb(OAc)4 did not provide the corresponding ring expanded compound, instead giving 2-(α-acetoxybenzylidene) -1,3-dithiane (3) in 69% yield.
DIMERIZATION OF 1-CYCLOPROPYL-1,3-BUTADIENE CATALYZED BY NICKEL(0)-TRIPHENYLPHOSPHINE COMPLEX
Authors: Murakami Masashi , Nishida Shinya
Published: July 2006

Abstract: Oligomerization of 1-cyclopropyl-1,3-butadiene (1) was accomplished by the catalytic action of nickel(0)-triphenylphosphine. The incorporation of the cyclopropane ring was evident since the dimer 2 isolated in ca. 50% was 4-cyclopropyl-1,5,7,9-undecatetraene. The head-to-head type structure of 2 was proved by the use of 1-cyclopropyl-4,4-dideuterio-1,3-butadiene (1d).
DIFFERENCE BETWEEN INFRARED MULTIPHOTON AND THERMAL REACTIONS OF HClC=CClH AND HClC=CCl2
Authors: Katayama Mikio , Mizugai Yoshihiro
Published: July 2006

The differences of mechanisms between the reaction induced by infrared multiphoton dissociation and pyrolysis are elucidated in the cases of 1,2-dichloroethylene and trichloroethylene. The interpretation presented here may be applied in the reactions of many molecules.
ASYMMETRIC SULFENYLATION OF KETONES WITH CHIRAL SULFENAMIDES
Authors: Hiroi Kunio , Nishida Michihisa , Nakayama Atsuko , Nakazawa Kumiko , Fujii Eiko , Sato Shuko
Published: July 2006

Asymmetric sulfenylations of 4-alkylcyclohexanones (6a,b) with chiral sulfenamides (1–5) were achieved in the presence of a catalytic amount of triethylamine hydrochloride to give 4-alkyl-2-phenylthiocyclohexanones (7a,b), which were transformed into optically active 4-alkyl-2-phenylthiocyclohexenes (10a,b) and 3-alkylcyclohexanones (11a,b) in fairly good chemical and optical yields. The influences of chiral sulfenamides and the reaction conditions on this asymmetric induction are described.
ELECTRON SPIN RESONANCE STUDIES ON THE CYCLOPENTADIENYL RADICALS. ON THE 13C HYPERFINE COUPLING CONSTANT AND SUBSTITUENT EFFECTS BY DEUTERIUM AND ALKYL GROUPS
Authors: Kira Mitsuo , Watanabe Mieko , Sakurai Hideki
Published: July 2006

ESR spectra of parent and six substituted cyclopentadienyl radicals (R–C5H4·; R=H, D, Me, Et, iso-pr, t-Bu, Me3SiCH2), generated from the corresponding R–C5H4–SnMe3 by an SH2 attack on Sn with the photochemically generated t-butoxy radical, are recorded and discussed.
MOLECULAR STRUCTURE OF AQUAETHYLENEDIAMINETETRAACETATOOSMIUM(IV) MONOHYDRATE: [Os (edta) (H2O)]·H2O
Authors: Saito Masami , Uehiro Takashi , Ebina Fujio , Iwamoto Toschitake , Ouchi Akira , Yoshino Yukichi
Published: July 2006

The title complex, obtained as the first characterized solid Os(IV)-edta complex, crystallizes in the monoclinic space group P21/a with a=14.956(7), b=8.181(3), c=14.600(7) Å, β=126.64(3)°, and Z=4. In the complex molecule [Os(edta)(H2O)], the seven-coordinate Os(IV) sits in a monocapped trigonal prism formed with two N and four O atoms of sexidentate edta and with an O atom of H2O.
SYNTHETIC CONTROL BY INTERNAL HYDROGEN BONDING. THE INTRAMOLECULAR DIELS–ALDER REACTION OF NITROFURAN AND α,β-UNSATURATED CARBOXAMIDES
Authors: Mukaiyama Teruaki , Takebayashi Toyonori
Published: July 2006

The intramolecular Diels–Alder reaction of N-(5-nitrofurfuryl)-N-(2-hydroxyphenyl) α,β-unsaturated carboxamides gives good yields of cycloadducts when internal hydrogen bonding is present.
PARTIAL ASYMMETRIC SYNTHESIS OF ATROPISOMERIC 1,1′-BINAPHTHYLS VIA THE ULLMANN COUPLING REACTION OF CHIRAL ALCOHOL ESTERS OF 1-BROMO-2-NAPHTHOIC ACID
Authors: Miyano Sotaro , Tobita Masayuki , Suzuki Shoji , Nishikawa Yukio , Hashimoto Harukichi
Published: July 2006

The Ullmann coupling of 1-bromo-2-naphthoates of C-chiral alcohols of R- and S-configuration induced axial dissymmetry of R- and S-chirality, respectively, in the newly formed 1,1′-bond of the binaphthyls; the optical yield amounted up to 13% where the chiral alcohol was l-menthol.
NEW AND EFFICIENT SYNTHESIS OF γ-KETO ESTERS FROM NITRO OLEFINS
Authors: Miyashita Masaaki , Kumazawa Toshiaki , Yoshikoshi Akira
Published: July 2006

The Lewis acid-catalyzed reaction of nitro olefins and ketene methyl trimethylsilyl acetals afforded methyl 4-oxo-carboxylates on hydrolysis of the resulting adducts followed by treatment with diazomethane.
ZEEMAN EFFECT AND TEMPERATURE DEPENDENCE OF NQR IN DIETHYLTIN DIBROMIDE AND DIIODIDE
Authors: Okuda Tsutomu , Hiura Morio , Boku Ryukei , Yamada Koji , Negita Hiaso
Published: July 2006

The Zeeman effects have been measured for both 81Br and 127I nuclei in diethyltin dihalides and the directions of electric field gradient axes have been determined. The temperature dependences of 127I NQR lines have shown anomalous features. The results were accounted for in terms of the intermolecular bonding.
PREPARATION AND DIELS–ALDER REACTIONS OF SOME FUNCTIONALIZED ISOPRENES
Authors: Mandai Tadakatsu , Yokoyama Haruyuki , Miki Toshio , Fukuda Haruo , Kobata Hiroshi , Kawada Mikio , Otera Junzo
Published: July 2006

A convenient synthetic method for some functionalized isoprenes employing 1-bromo-2-phenylthioethane and ethyl acetoacetate as starting materials is reported. It has also been found that the dienes thus obtained gave functionalized limonene analogs by Diels–Alder reaction with methyl vinyl ketone.
A NEW STEREOSELECTIVE SYNTHESIS OF A TERPENOID DIOL COMPONENT OF THE PHEROMONAL SECRETION OF THE QUEEN BUTTERFLY
Authors: Masaki Yukio , Sakuma Kazuhiko , Kaji Kenji
Published: July 2006

A terpenoid diol component of the pheromonal secretion of the queen butterfly was synthesized stereoselectively from geraniol by means of a site-specific terminal olefin functionalization and the subsequent anionic [2,3]-sigmatropic rearrangement of carbomethoxymethyl allylic sulfide.
CATALYTIC REDUCTION OF CO2 TO CO USING SULFUR VAPOR AS A REDUCING REAGENT
Authors: Ueno Akifumi , Sato Toshio , Todo Naoyuki , Kotera Yoshihide , Takasaki Seiji
Published: July 2006

The catalytic reduction of CO2 to CO by sulfur vapor was studied at the temperatures higher than 650°C over various metal oxides and sulfides, and on the basis of the results from the kinetic studies and the X-ray diffraction measurements, the reaction scheme was tentatively proposed as follows:

metal oxides + S2(g) → metal sulfides + SO2

metal sulfides + CO2 → metal oxides + CO + SO2.
ASYMMETRIC INDUCTION IN THE [2,3] SIGMATROPIC REARRANGEMENT VIA CHIRAL AMMONIUM YLIDES
Authors: Hiroi Kunio , Nakazawa Kumiko
Published: July 2006

The asymmetric [2,3] sigmatropic rearrangements of the chiral ammonium chlorides (E)-(3a,b) were achieved upon treatment with t-BuOK followed by acidic hydrolysis of the aminonitriles (5a,b) obtained to give (R)-(+)-2-methyl-2-phenyl-3-butenal (6). The rearrangement of (E)-(3a) at −78° resulted in the highest optical yield (90%) of (R)-(+)-(6). The geometrical isomer (Z)-(3a) underwent the same [2,3] shift under the same conditions to afford (S)-(−)-(6). The mechanism of this asymmetric induction is discussed based on these results.
CHELATOMETRIC DETERMINATION OF RHODIUM(III) USING WATER-ETHANOL SOLUTIONS
Authors: Yoshino Yukichi , Hatazawa Satoshi , Saito Masami , Ouchi Akira
Published: July 2006

An EDTA back-titration of rhodium(III) has been proposed taking advantage of rapid chelation in water-ethanol solutions. The optimum amount of rhodium was 0.5 – 10 mg and the standard deviation was 0.76%. The method is applicable to the analysis of some rhodium(III) complexes.
NMR STUDIES ON THE INTERACTIONS OF GLYMES WITH DIMETHYLTIN DICHLORIDE IN BENZENE
Authors: Otera Junzo , Shiigi Masanobu , Kawasaki Yoshikane
Published: July 2006

The interactions between glymes (Gly) and dimethyltin dichloride (DMTC) have been studied by 1H NMR spectroscopy. The coexistence of the 1:2 Gly/DMTC complexes with 1:1 complexes was found for the higher members of Gly. Benzene-induced shifts of proton signals of both DMTC and Gly suggest that the complexes possess the methyl groups attached to tin essentially in a trans arrangement.
PREFERRED CONFORMATIONS OF 9-MONOSUBSTITUTED DERIVATIVES OF 8,9,10,11-TETRAHYDRO-7H-CYCLOOCTA[de]NAPHTHALENE
Authors: Kamada Toshihiro , Yamamoto Osamu
Published: July 2006

The conformations of 8,9,10,11-tetrahydro-7H-cycloocta[de]naphthalen-9-ol and its esters have been studied based on the NMR spectra. It was found that these compounds assume solely the equatorial-boat (eb) conformations in solution, the peri rings of which are unusually rigid as compared with the conformations previously reported.
CLEAVAGE OF PEPTIDE TO SPARROW-RESIN BOND BY CATALYTIC TRANSFER HYDROGENOLYSIS WITH 1,4-CYCLOHEXADIENE
Authors: Colombo Roberto
Published: July 2006

Cleavage of benzyl ester-type linkage to the Sparrow modified polystyrene support was attempted with the aid of catalytic transfer hydrogenation using 1,4-cyclohexadiene and palladium black, and satisfactory yields were obtained. This will provide an alternatively efficient and mild method for the final deblocking step during improved solid phase peptide synthesis.
ONE-POT SYNTHESIS OF (Z)-4-ALKENOIC ACIDS
Authors: Fujisawa Tamotsu , Sato Toshio , Kawara Tatsuo , Naruse Kouichi
Published: July 2006

The reaction of β-propiolactone with di-(Z)-1-alkenylcuprates, prepared from Grignard reagents, copper(I) iodide and acetylene, gave (Z)-4-alkenoic acids in high yields in one-pot operation.
HALOGENATION OF 2,7-DI-TERT-BUTYL-TRANS-10b,10c-DIALKYL-10b,10c-DIHYDROPYRENES
Authors: Tashiro Masashi , Yamato Takehiko
Published: July 2006

Treatment of 2,7-di-tert-butyl-trans-10b,10c-dialkyl-10b,10c-dihydropyrene 5a–5c with bromine afforded the corresponding tetrabromides 7a–7c in good yields, respectively. The tetrachloro derivative of 5a was also obtained in 40% yield by the treatment of 5a with SO2Cl2. The bromination of 5a–5c with bromine in the presence of Fe powder gave the dealkylated compound 2,7-di-tert-4,5,9,10-tetrabromopyrene 8 in good yields, respectively. When 5a–5c were treated with I2 2,7-di-tert-butylpyrene 9 was obtained in good yields, in all cases.
OXIDATION OF ASCORBIC ACID CATALYZED BY N,N′-ETHYLENEBIS(SALICYLIDENEAMINATO)COBALT(II)
Authors: Tsukahara Keiichi , Ushio Hiroko , Yamamoto Yasuo
Published: July 2006

N,N′-Ethylenebis(salicylideneaminato)cobalt(II) catalyzed the autoxidation of ascorbic acid in methanol. The kinetic evidence of a transient-oxygen complex with ascorbic acid was obtained by the measurements of the oxygen consumption in this catalytic oxidation.
REDUCTIVE COUPLING OF AROMATIC ALDEHYDES BY OCTACARBONYL DIFERRATE
Authors: Ito Keiji , Nakanishi Saburo , Otsuji Yoshio
Published: July 2006

The reaction of aromatic aldehydes with Fe(CO)5 or Fe3(Co)12 in pyridine gives the corresponding 1,2-diaryl-1,2-ethanediols as major products in good yields. A reactive species of this reaction is octacarbonyl diferrate [Fe2(CO)8]2−.
PHOTOCHEMICALLY INDUCED REDUCTION OF VIOLOGENS IN SOLID POLAR APROTIC POLYMER MATRICES
Authors: Kamogawa Hiroyoshi , Masui Toshiaki , Nanasawa Masato
Published: July 2006

Photochemically induced reversible reduction of viologens in solid polar aprotic polymer matrices proceeds much more efficiently than that in protic ones. The effects of the N-substituent and anionic part of viologens were also considerable.
LASER-PHOTOLYSIS STUDY OF THE EXTERNAL MAGNETIC FIELD EFFECT UPON THE PHOTODECOMPOSITION REACTION OF 1,3-DIPHENYL-2-PROPANONE IN A MICELLE
Authors: Hayashi Hisaharu , Sakaguchi Yoshio , Nagakura Saburo
Published: July 2006

The photodecomposition reaction of 1,3-diphenyl-2-propanone in a micelle was studied with the aid of ns laser-photolysis. The transient absorption due to the benzyl radical was observed and the amount of escaping benzyl radicals from radical pairs was found to be enhanced by 30 % in the presence of a magnetic field of 70 mT.
KINETIC STUDIES ON THE LABILE TERNARY NICKEL(II) CHELATES OF N-DISUBSTITUTED DITHIOCARBAMIC ACIDS BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
Authors: Moriyasu Masataka , Hashimoto Yohei
Published: July 2006

The labile ternary complex formed by mixing two solutions of nickel(II) dialkyldithiocarbamate solutions was separated by high-performance liquid chromatography. The equilibrium constant and rate constants of formation and disproportionation of the ternary complex were obtained.
SEPARATION OF LANTHANOIDS WITH TETRAETHYLENE GLYCOL
Authors: Hirashima Yoshiyuki , Moriwaki Yoshikazu , Shiokawa Jiro
Published: July 2006

The yield of the solid complex of tetraethylene glycol(EO4) with a lanthanoid(Ln) nitrate decreases with increasing atomic number of Ln, and is greatly affected by H2O present in the solution. The separation factors of EO4 are comparable to those of the separating reagents practically used.
REGULARITY OF THE OXIDIZING ACTIVITY OF Mo6+ IONS IN VARIOUS 12-HETEROPOLYMOLYBDATES
Authors: Akimoto Masamichi , Tsuchida Yoshitaka , Echigoya Etsuro
Published: July 2006

The oxidizing activity of Mo6+ ions in 12-heteropolymolybdates was found to correlate with the electronegativity of counter ion (H+, alkali, and alkali-earth metal ions) as well as of hetero atom (P5+, As5+, and Si4+).
NOVEL RUTHENIUM(II) OLEFIN COMPLEX WITH A COORDINATED ALICYCLIC CARBON–HYDROGEN BOND
Authors: Itoh Kenji , Oshima Noriaki
Published: July 2006

Chloro(η2,η2-norbornadiene) [η1,η2-3-endo-(3′-nortricyclyl)norborn-5-en-2-endo-yl]ruthenium(II), 1a, prepared by zinc reduction of [RuCl2(norbornadiene)]n in the presence of norbornadiene and suitable proton sources such as alumina or ammonium chloride in acetonitrile, involves a coordinated alicyclic carbon–hydrogen bond.
CRYSTAL GROWTH OF Na(La,Nd)(WO4)2 SOLID SOLUTION FROM HIGH-TEMPERATURE SOLUTIONS
Authors: Oishi Shuji , Tate Isao
Published: July 2006

Na(La,Nd)(WO4)2 solid solution crystals were grown from high-temperature solutions of La2O3–Nd2O3–WO3–Na2CO3 by slow cooling. These crystals were tetragonal, up to 4–5 mm in size, red purple and mostly transparent. The lengths of a and c axes were considered to obey Vegard’s law. This experimental result indicated that the complete series of solid solution isostructural with the end member crystals were obtained.
AMIJIDICTYOL, A NEW DITERPENOID FROM THE BROWN SEAWEED DICTYOTA LINEARIS: X-RAY CRYSTAL AND MOLECULAR STRUCTURE
Authors: Ochi Masamitsu , Watanabe Masanori , Kido Masaru , Ichikawa Yasuji , Miura Iwao , Tokoroyama Takashi
Published: July 2006

The structure of a new diterpenoid, amijidictyol, isolated from the brown seaweed Dictyota linearis has been determined as 4 on the basis of spectral evidence and X-ray analysis.
UNUSUAL HIGH REACTIVITIES OF 5α- AND 5β-CHOLESTAN-3-ONES IN THE HYDROGENATION CATALYZED BY PALLADIUM. EVIDENCE FOR AN ATTRACTIVE INTERACTION OF THE STEROID α-FACE WITH PALLADIUM
Authors: Nishimura Shigeo , Murai Mikio , Shiota Michio
Published: July 2006

5α- And 5β-cholestan-3-ones are 30 and 17 times as reactive as 4-t-butylcyclohexanone in Pd catalyzed competitive hydrogenation in t-BuOH. The high reactivity of the steroid ketones and unusual hydrogenation stereochemistry on Pd have been explained on the basis of an attractive interaction of the steroid α-face with Pd.
SYNTHESIS OF THE SULFUR ANALOG OF Δ6-PGI1
Authors: Shibasaki Masakatsu , Torisawa Yasuhiro , Ikegami Shiro
Published: July 2006

A synthesis of the sulfur analog of Δ6-PGI1 with potent inhibitory activity in platelet aggregation is described. The synthesis starting from the suitably protected Corey lactone includes the hydroxylation of the lactone and the novel intramolecular addition of the sulfenyl bromide.
GENERAL BASE CATALYSES BY α-CYCLODEXTRIN IN THE HYDROLYSES OF ALKYL BENZOATES
Authors: Komiyama Makoto , Hirai Hidefumi
Published: July 2006

The hydrolyses of seven alkyl benzoates are catalyzed by α-cyclodextrin. These results indicate that the general base catalysis by α-cyclodextrin, previously found for the first time in the hydrolysis of 2,2,2-trifluoroethyl 4-nitrobenzoate, is applicable to other alkyl esters.
ASYMMETRIC TRANSFORMATION OF AMINO ACIDS IN N-SALICYLIDENE AMINO ACYL-l-ISOLEUCINATOCOPPER(II)
Authors: Harada Kaoru , Shiono Katsuji , Nomoto Shinya
Published: July 2006

A new asymmetric transformation of amino acids was described. Thus, when N-salicylidene-d-alanyl-, d-phenylalanyl-, or d-phenylglycyl-l-isoleucinatocopper(II) was incubated at pH 8.5 and 80°C, the resulting mixture at equilibrium contained a complex of l-l-dipeptide in the contents of 63–76%. The epimerization of dipeptides is based on the enhanced activity of N-terminal amino acids through complex formation.
AN EFFECTIVE DEHYDROGENATION OF INDOLINES TO INDOLES WITH COBALT(II) SCHIFF’S BASE COMPLEXES
Authors: Inada Akira , Nakamura Yushin , Morita Yutaka
Published: July 2006

Facile dehydrogenations of indolines to indoles were performed with the catalytic amount of bis(salicylidene)ethylenediaminatocobalt(II) and bis(3-methoxysalicylidene)ethylenediaminatocobalt(II) under mild conditions in 55–92% yields.
ON THE ROTATION VERSUS THE INVERSION MECHANISM IN THE THERMAL ISOMERIZATION OF CIS-AZOBENZENES
Authors: Shinkai Seiji , Kusano Yumiko , Shigematsu Kazuyoshi , Manabe Osamu
Published: July 2006

The thermal cis-to-trans isomerization of an azobenzene covalently-bridged to azacrown ether occurs via the inversion mechanism, and the rotational mechanism is not allowed owing to the rigid ring structure. By using the “standard” azobenzene, it was demonstrated that the thermal isomerization of most cis-azobenzenes occurs via the inversion mechanism, the activation parameters being subject to a good ΔH\eweq–ΔS\eweq compensation relationship.
REACTION OF α-BROMO-α,β-UNSATURATED ESTERS AND BUTENOLIDES WITH MALONAMIC ESTERS
Authors: Takei Hisashi , Fukuda Yoshimasa , Sugaya Kazuhiro , Taguchi Takeo , Kawara Tatsuo
Published: July 2006

α-Bromo-α,β-unsaturated esters and α-bromobutenolides reacted with sodium salts of methyl malonamates to afford cyclopropanes, α-methoxycarbonyllactams and 5-amino-4-methoxycarbonyl-2,3-dihydrofurans. The last compounds could be easily converted into α-methoxycarbonyl-γ-lactones. The ratio of these compounds formed is influenced by the structures of both malonamates and unsaturated compounds, especially by the substituents at nitrogen of the malonamates, and by the reaction conditions.
MULTIPLE PATHS FOR PHOTOALKYLATION OF PYRIDINECARBOXYLIC ESTERS IN ALCOHOLS
Authors: Sugiyama Toru , Tobita Estuo , Takagi Kyoko , Sato Michitsugu , Kumagai Yasuyuki , Satô Gen P , Sugimori Akira
Published: July 2006

Photochemical substitution of ring hydrogen of pyridinecarboxylic esters by alkyl groups derived from solvent alcohols occurs in several paths: 1) alkylation initiated by the excited carbonyl moiety of the ester group and 2) alkylation initiated by the excitation of the π-electonic system of the pyridine ring. In the photoreaction of methyl 3-pyridinecarboxylate in acidic methanol, three types of excited state (two triplet states for alkylation and a singlet state for alkoxylation) contribute simultaneously.
ANODIC OXIDATION OF PYRONES AND RELATED COMPOUNDS
Authors: Iguchi Masanobu , Nishiyama Atsuko , Eto Hideo , Yamamura Shosuke
Published: July 2006

Triacetic lactone, 4-hydroxycoumarins, and kojic acid derivative were subjected to anodic oxidation in MeOH containing LiClO4 or NaCN to afford the corresponding methoxy or cyano compounds. In a basic media, however, dipyrone and dicoumarol were produced from triacetic lactone and 4-hydroxycoumarin, respectively. The formation process of 3-methoxytriacetic lactone as well as of 3-cyanotriacetic lactone is also presented.
A CONVENIENT SYNTHESIS OF ACETYLENIC KETONES FROM β-DIKETONES USING α,α-DIFLUOROALKYLAMINES AND FREEZE-DRIED POTASSIUM FLUORIDE
Authors: Kitazume Tomoya , Ishikawa Nobuo
Published: July 2006

α,α-Difluoroalkylamines, such as 1-diethylamino-2-chloro-1,1,2-trifluoroethane (1) and 1-diethylamino-1,1,2,3,3,3-hexafluoropropane (2), were found to be useful dehydrating agents for the synthesis of acetylenic ketones from β-diketones in the presence of freeze-dried potassium fluoride in acetonitrile.
EFFECT OF OXYGEN ON THE PHOTOSTATIONARY STATE COMPOSITION IN TRIPLET SENSITIZED ISOMERIZATION OF 3,3-DIMETHYL-1-(2-NAPHTHYL)-1-BUTENE
Authors: Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

Photostationary state compositions and quantum yields were determined for triplet sensitized isomerization of 3,3-dimethyl-1-(2-naphthyl)-1-butene in benzene. The ratio of the trans isomer at the photostationary state increased with increasing concentration of oxygen, which, combined with the azulene effect, indicates that both of transoid and twisted triplets are quenched by oxygen.
CHEMICAL SYNTHESIS OF BISDEPHOSPHO LIPID A OF Salmonella ENDOTOXIN
Authors: Inage Masaru , Chaki Haruyuki , Kusumoto Shoichi , Shiba Tetsuo , Tai Akira , Nakahata Masaaki , Harada Tadao , Izumi Yoshiharu
Published: July 2006

Synthesis is described on 6-O-[2-deoxy-2-((R)-3-hydroxytetradecanoylamino)-6-O-tetradecanoyl-β-d-glucopyranosyl]-2-deoxy-2-((R)-3-hydroxytetradecanoylamino)-3,4-di-O-tetradecanoyl-d-glucopyranose which corresponds to the phosphate-less lipid A structure of Salmonella-type bacterial endotoxin.
STRUCTURE AND CHEMICAL SYNTHESIS OF ME-IQ, A POTENT MUTAGEN ISOLATED FROM BROILED FISH
Authors: Kasai Hiroshi , Yamaizumi Ziro , Wakabayashi Keiji , Nagao Minako , Sugimura Takashi , Yokoyama Shigeyuki , Miyazawa Tatsuo , Nishimura Susumu
Published: July 2006

Structure of a mutagenic compound (Me-IQ) isolated from broiled fish was determined to be 2-amino-3,4-dimethylimidazo[4,5-f]quinoline based on the mass-, UV- and 1H-NMR-spectra and chemical synthesis. Me-IQ showed strong mutagenic activity towards Salmonella typhimurium TA98 in the presence of S-9 mix.
VALENCE CHANGE OF COPPER IN CATALYTIC OXIDATION OF l-ASCORBIC ACID BY MOLECULAR OXYGEN
Authors: Ito Sotaro , Yamamoto Toshimasa , Tokushige Yuji
Published: July 2006

The copper(II) chloride-catalyzed oxidation of l-ascorbic acid (AA) by O2 was found to involve both the anaerobic oxidation of AA by copper(II) chloride and the reoxidatian steps of copper(I) chloride by O2 in the catalytic cycle, by comparing the rate of copper(II)-catalyzed oxidation of AA by O2 (RAIIO) with those of anaerobic oxidation of AA by copper(II) (RAII) and oxidation of copper(I) by O2 (RIO).
OXYGEN ADSORPTION SITES OF Fe2O3–Sb2O4 CATALYST DETERMINED BY SECONDARY ION MASS SPECTROMETRY-18O TRACER METHOD
Authors: Aso Isao , Amamoto Taro , Yamazoe Noboru , Seiyama Tetsuro
Published: July 2006

In an attempt to determine oxygen adsorption sites of the Fe2O3–Sb2O4 catalysts, SIMS measurements of the catalysts were performed after 18O2 preadsorption (SIMS-18O tracer method). It was clearly shown that the adsorbed oxygen was accommodated by the surface Sb ions.
TIME-AVERAGED CONFORMATIONS OF THE INCLUSION COMPLEXES OF β-CYCLODEXTRIN WITH t-BUTYLPHENOLS
Authors: Komiyama Makoto , Hirai Hidefumi
Published: July 2006

Time-averaged position of phenol, p-t-butylphenol or m-t-butyl phenol in the cavity of β-cyclodextrin in aqueous solution is determined by using the 1H-NMR spectroscopy. The order of the rate constants of the β-cyclodextrin-accelerated cleavages of the corresponding acetyl esters is satisfactorily interpreted in terms of the time-averaged positions of the substrates estimated from those of the phenols.
A FACILE SILYLATION OF CARBOXYLIC ACIDS WITH HEXAMETHYLDISILOXANE
Authors: Matsumoto Hideyuki , Hoshino Yoshikazu , Nakabayashi Jiro , Nakano Taichi , Nagai Yoichiro
Published: July 2006

It was found that, in the presence of a catalytic amount of sulfuric acid, hexamethyldisiloxane silylates carboxylic acids to give trimethylsilyl carboxylates in good yields.
SYNTHESIS AND PROPERTIES OF 2-CYCLOHEPTATRIENYLIDENE-5-DICYANOMETHYLIDENE-2,5-DIHYDROTHIOPHENE (A THIOPHENE ANALOG OF [1.6.7]QUINARENE)
Authors: Takahashi Kazuko , Takase Kahei , Sakae Toshisada
Published: July 2006

The title compound 2 was prepared in 7 steps starting from 2-bromo-5-(cycloheptatrienyl)thiophene. While the [1.6.7]quinarene derivative 1 can not be isolated in a monomeric solid due to easy and reversible oligomerization, the thiophene analog 2 is stable as a monomer both in solid and in solution. The responsible factors for the oligomerization reaction were discussed based on the chemical and physical properties of these quinarenes 1 and 2.
2,5-DIAZACYCLOPENTADIENYUDENE: A STANDARD CARBENE OR A HIGHLY REACTIVE DIRADICAL ?
Authors: Bru Núria , Vilarrasa Jaume
Published: July 2006

2,5-Diazacyclopentadienylidene (2H-imidazolylidene), generated either by photolysis or thermolysis from 2-diazo-2H-imidazole, reacts with benzene derivatives to give mainly a mixture of o-, m-, and p-substituted 2-phenylimidazoles. The carbene shows a strong diradical character, in sharp contrast with the well-known behavior of cyclopentadienylidene.
CYCLOADDITION REACTION OF 3-CYANOINDOLIZINES WITH DIMETHYL ACETYLENEDICARBOXYLATE —FORMATION OF CYCL[3.2.2]AZINES AND 1:2 ADDUCTS
Authors: Uchida Takane , Matsumoto Kiyoshi
Published: July 2006

3-Cyano- and 3-cyano-6,8-dimethylindolizines (1a) and (1b) react with dimethyl acetylenedicarboxylate in refluxing toluene in the presence of Pd–C to give the cycl[3.2.2]azines (4a) and (4b), respectively, while 3-cyano-7-methyl- and 3-cyano-7-benzylindolizines (1c) and (1d) affording the 1:2 adducts (6c) and (6d) along with cycl[3.2.2]azine (4d).
13C CONTACT SHIFTS OF AROMATIC AMINES INDUCED BY GD(FOD)3 AND SPIN DELOCALIZATION MECHANISM: EVIDENCE FOR THE OCCURRENCE OF DIRECT SPIN TRANSFER
Authors: Hirayama Masatoshi
Published: July 2006

The 13C contact shift patterns of several aromatic amines induced by Gd(fod)3 have clearly been interpreted by the superposition of σ-type delocalization of positive spin transferred directly into C1 from the Gd ion and π-type delocalization of the negative spin introduced into the N-lone pair orbital.
RAPID EXCHANGE OF OXYGEN-18 BETWEEN WATER VAPOR AND HETEROPOLY COMPOUNDS BY DIFFUSION OF CRYSTAL WATER
Authors: Sakata Kanji , Misono Mokoto , Yoneda Yukio
Published: July 2006

By means of in situ IR measurement, it was found that rapid and reversible 18O-exchange took place between all bulk oxygen atoms, but P-O oxygen, of 12-molybdophosphoric acid and water vapor, maintaining the Keggin structure. The rapid exchange is likely due to the rapid diffusion of water molecules in the bulk.
COMPARISON OF RUTHENIUM COMPLEXES FOR PHOTOINDUCED METHYL VIOLOGEN REDUCTION AND HYDROGEN EVOLUTION FROM WATER BY HYDROGENASE
Authors: Okura Ichiro , Kim-Thuan Nguyen
Published: July 2006

Highly active photoinduced systems for methyl viologen reduction are developed by using ruthenium complexes with long lifetime at the photoexcited state. The system, which has the higher activity for methyl viologen reduction, has the higher activity for hydrogen evolution when hydrogenase [EC 1.12.2.1] was added.
TRANSPOSITION OF CO2 GROUP IN 2-FURANONES CATALYZED BY PALLADIUM (0)
Authors: Inoue Yoshio , Hibi Takuo , Kawashima Yasuhiko , Hashimoto Harukichi
Published: July 2006

3,3-Dialkyl-4-methylenedihydro-2(5H)-furanone 1 isomerized into another furanone, 4-methyl-5,5-dialkyl-2(5H)-furanone 2 with transpositin of the CO2 group in the presence of a catalytic amount of Pd(diphos)2[diphos=Ph2PCH2CH2PPh2].
BUTTRESSING EFFECT IN OPPOSITE DIRECTION
Authors: Yamamoto Gaku , Suzuki Masahiko , Oki Michinori
Published: July 2006

Rotational barrier in 1,2,3,4-tetrachloro-9-(1,1-dimethyl-2-phenylethyl)triptycene was 1.8 kcal/mol lower than that in the corresponding 1,4-dichloro derivative. This apparently anomalous “reverse” buttressing effect may be originated from the tilting of the 9-substituent away from the peri-chloro group in this highly congested system.
ADSORPTION OF CESIUM FROM AQUEOUS SOLUTIONS USING A CRYSTALLINE HYDROUS TITANIUM DIOXIDE FIBERS
Authors: Komatsu Yu , Fujiki Yoshinori
Published: July 2006

The adsorption of cesium in aqueous solutions has been studied by using an ion-exchanger of crystalline hydrous titanium dioxide fibers. Cesium can be perfectly adsorbed from alkaline solutions, and the distribution ratio of cesium is higher than that of lithium, sodium, potassium, or rubidium. This method can be applied to cesium immobilization in the radwastes under mild alkaline conditions.
LIPOSOME IMMUNOELECTRODE
Authors: Shiba Kunio , Watanabe Tokuko , Umezawa Yoshio , Fujiwara Shizuo , Momoi Hironao
Published: July 2006

A new immunoelectrode system is reported, where thin-layer potentiometric measurement of complement and antibody levels in microliter serum was performed using tetrapentylammonium ion(TPA+) loaded liposomes and TPA+ ion selective electrode.
PREPARATION OF (−)-(M)-[2.2]PARACYCLOPHANO-HEXAHELICENE FROM (−)-(M)-1,4-DIMETHYLHEXAHELICENE AND ABSOLUTE CONFIGURATION OF 4-SUBSTITUTED [2.2]PARAOYCLOPHANES
Authors: Nakazaki Masao , Yahamoto Koji , Maeda Miharu
Published: July 2006

Photo-cyclization of a cis–trans mixture of the 1,2-diarylethylene precursor 1 gave 1,4-dimethylhexahelicene (2) whose levorotatory enantiomer with (M)-helicity was converted into (−)-(M)-[2.2]paracyclophano-hexahelicene (7), mp 236–237°C, [α](abs)577-5520°1) confirming the (R)-configuration previously assigned to (−)-[2.2]paracyclophanecarbaldehyde (8).
CHALCOMORACIN, A NATURAL DIELS–ALDER ADDUCT FROM DISEASED MULBERRY
Authors: Takasugi Mitsuo , Nagao Shigemitsu , Masamune Tadashi , Shirata Akira , Takahashi Kokichi
Published: July 2006

The structure elucidation of a new phytoalexin, isolated from diseased mulberry leaves and designated as chalcomoracin, is described. The compound is regarded biogenetically as a Diels–Alder adduct of a chalcone, isolated newly from diseased mulberry shoots, and a substituted 2-phenylbenzofuran.
ELECTROLYTIC METHANOLYSIS OF ACYLATED AMINO SUGARS
Authors: Imagawa Takeshi , Nakashima Yasushi , Kawanisi Mituyosi
Published: July 2006

Electrolysis of 2-acetamido-1,3,4,6-tetra-O-acetyl-2-deoxy-α- or β-d-glucose in methanol gives specifically 1-deacetylated product, 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-d-glucose, while methyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-d-glucoside is deacetylated to yield 2-acetamido-6-O-acetyl-2-deoxy-and 2-acetamido-2-deoxy-α-d-glucosides.
FIRST SYNTHESIS OF AN EPIMER OF (±)-PENTENOMYCIN I
Authors: Shono Tatsuya , Matsumura Yoshihiro , Yamane Shin-ichiro , Suzuki Masahito
Published: July 2006

An epimer of pentenomycin I was first synthesized starting from a furan derivative. The synthetic route involves acid-catalyzed transformation of a 2,5-dihydro-2,5-dimethoxyfuran derivative to a cyclopentenone derivative, which is a key intermediate in the synthesis of the expected compound.
ADSORPTION OF URANIUM ION IN SEA WATER ON COPRECIPITATED SILICA-TITANIA GEL
Authors: Kaneko Shoji , Okuda Shungo , Nakamura Motoshi , Kubo Yasushi
Published: July 2006

Homogeneously coprecipitated silica-titania gel was shown to exhibit selectively high adsorptive ability for uranium ion in sea water. More than 90% of the adsorbed uranium ion on the gel was eluted with ammonium carbonate solution. The recovery percentage of the ion was found to be above 80%.
RATES OF DISSOCIATION OF N,N-DIBENZYLANILINIUM IONS IN APROTIC SOLVENTS
Authors: Oki Michinori , Yoshioka Yasuhiro , Kihara Hiroshi , Nakamura Nobuo
Published: July 2006

Rates of dissociation of N,N-dibenzylanilinium ions into N,N-dibenzylaniline and proton which is captured by chloride anion have been determined by the dynamic NMR technique. The method supplies information about proton affinities of amine and anion in aprotic solvents.
NITROGEN-15 NUCLEAR MAGNETIC RESONANCE OF [MET5]-ENKEPHALIN: SIGNAL ASSIGNMENTS AND THE EFFECT OF pH TO THE CHEMICAL SHIFTS
Authors: Higuchi Naoki , Kyogoku Yoshimasa , Yajima Haruaki
Published: July 2006

Natural abundance 15N nmr spectra of [Met5]-enkephalin and its constituent peptides were obtained. By comparison of these spectra five 15N resonance signals could be assigned to each amino acid residue. In the pH titration curves of the chemical shifts the effect of the protonation at the C-terminal Met carboxyl group was observed.
SYNTHESIS OF 2-AMINO-2-DEOXY-α-d-GLUCOPYRANOSYL β-d-FRUCTOFURANOSIDE (2-AMINO-2-DEOXY-SUCROSE
Authors: Koto Shinkiti , Inada Shigeru , Zen Shonosuke
Published: July 2006

2-Amino-2-deoxy-α-d-glucopyranosyl β-d-fructofuranoside (2-amino-2-deoxy-sucrose) was synthesized by condensation of 3,4,6-tri-O-acetyl-2-(2,4-dinitroanilino)-2-deoxy-α-d-glucopyranosyl bromide and 1,3,4,6-tetra-O-benzyl-d-fructofuranose with the aid of silver perchlorate and tribenzylamine in benzene, followed by removal of protecting groups.
ASYMMETRIC INDUCTION IN FREE RADICAL ADDITION OF THIOLS TO l-MENTHYL CROTONATE
Authors: Yoshihara Masakuni , Fujihara Hisashi , Maeshima Toshihisa
Published: July 2006

Diastereoface differentiation of l-menthyl crotonate has been achieved in the radical addition with achiral thiols such as thiolacetic acid, mercaptoacetate, and mercaptoacetic acid.
THE FACILE SYNTHESIS OF 2,6-DIAMINO-l,3,5,7-TETRAZACYCOPENT[f]AZULENE
Authors: Yasunami Masafumi , Sasagawa Yasuhiko , Takase Kahei
Published: July 2006

2,6-Diamino-l,3,5,7-tetrazacyclopent[f]azulene, a parent compound of zoanthoxanthins, was synthesized from 5,7-dibromo-2-methoxytropone by two step condensation with guanidine.
A SURPRISING DIFFERENCE IN REACTIVITIES OF 1,2,3,4-TETRACHLORO-9-(2-CHLORO-1,1-DIMETHYLETHYL)TRIPTYCENE ROTAMERS. A REACTION CATALYZED BY LEWIS ACIDS
Authors: Kikuchi Hiromi , Mitsuhashi Tsutomu , Nakamura Nobuo , Oki Michinori
Published: July 2006

±sc-1,2,3,4-Tetrachloro-9-(2-chloro-1,1-dimethylethyl)triptycene was found to react in the presence of TiCl4 at room temperature, whereas the ap isomer required SbCl5 to react. Both gave practically the same mixture of 1,2-dimethyl-7,8,9,10-tetrachloro-1,2,6,10b-tetrahydro-6,10b-o-benzenoaceanthrylenes. The structures of the products were confirmed by independent syntheses.
CYCLOADDITION OF IMIDAZO[2,1-b]THIAZOLES AND THIAZOLO[3,2-a]BENZIMIDAZOLE WITH DIMETHYL ACETYLENEDICARBOXYLATE
Authors: Abe Noritaka , Nishiwaki Tarozaemon , Komoto Noriko
Published: July 2006

Cycloadditions of imidazo[2,1-b]thiazole and thiazolo[3,2-a]benzimidazole with dimethyl acetylenedicarboxylate follow dual courses producing pyrrolo[2,1-b]thiazoles in an aprotic nonpolar solvent or imidazo[1,2-a]pyridines in an aprotic polar solvent.
SYNTHESES AND PROPERTIES OF TRIMETHYLBISDEHYDRO[19]ANNULENONES AND THE BENZANNELATED DERIVATIVES
Authors: Qjima Juro , Wada Kazuyo , Nakagawa Yukiko , Terasaki Masayuki , Juni Yasushi
Published: July 2006

Syntheses of 2,7,12-trimethyl- 5, 7,12,19-trimethyl-8,10-bisdehydro- 6, 14-methylbenzo[h]-10,12-bisdehydro- 7, and 2-methyldibenzo[f,1]-8,10-bisdehydro[19]annulenone 8 are described. The effects of α-methyl substitution and benzannelation for the bisdehydro[19]annulenone ring system are discussed.
BIOTRANSFORMATION OF FOREIGN SUBSTRATES WITH CALLUS TISSUES. TRANSFORMATION OF TERPINEOLS WITH TOBACCO SUSPENSION CELLS
Authors: Suga Takayuki , Aoki Tadashi , Hirata Toshifumi , Lee Ym Sook , Nishimura Osamu , Utsumi Masafumi
Published: July 2006

Biotransformation of foreign substrates with the suspension cells of Nicotiana tabacum was tested with α-terpineol (I), trans-β-terpineol (II), and trans-β-terpinyl acetate (III). It was found that the cultured cells have the ability to hydroxylate the C–C double bond itself as well as its allylic positions.
THE USE OF PRE-COLUMN TO AVOID THE INTERFERENCE OF POLYAMIDES(NYLONS) IN THE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC ANALYSIS OF SALICYLATES
Authors: Saotome Toshiyuki , Ogasawara Yoshio , Ishijima Itaru , Masuda Nobuo
Published: July 2006

A new liquid chromatographic procedure for the determination of salicylic acid and its derivatives in the presence of nylon has been developed. By using pre-column(packing material; silica gel) and main-column(packing material; Hitachi gel 3011), salicylates could be easily determined by means of a UV detector (at 254nm) without any interference of nylon. The average salicylates recovery over a concentration range of 50–800 μg/ml was 99.7±1.3%.