bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of Oxidation of Carbonyl Compounds by Peroxomonosulfate. Acetaldehyde, Propionaldehyde, and Butyraldehyde
Authors: Ramachandran M S , Vivekanandam T S , Arunachalam V
Published: July 2006

A kinetic study of oxidation of acetaldehyde, propionaldehyde, and butyraldehyde by peroxomonosulfate (PMS) in the presence of H+ ion has been carried out. The reaction shows first order dependence each on [PMS] and [Aldehyde]. The reaction shows inverse first order over a particular concentration range of H+ ion and beyond that first order dependence is observed with respect to [H+]. The inverse hydrogen ion dependence on kobsd may be due to the higher reactivity of SO52− than HSO5− with aldehydes. The increase in kobsd with increase in [H+] beyond certain [H+] can be explained by the formation of protonated carbonyl compounds. The Taft’s plot gives ρ* value of ≈5.0 indicating that the reaction is nucleophilic substitution at the carbonyl carbon which then rearranges to products.
Syntheses and Properties of Pentatrideca-, Pentapentadeca-, Pentaheptadeca-, and Pentanonadecafulvalene Derivatives
Authors: Ojima J\={u}ro , Itagawa Kazunori , Nakada Tetsuya
Published: July 2006

5,10-Dimethyl-6,8-bisdehydropentatridecafulvalene 11, 10-methyl-6,8-bisdehydro-4,5-benzopentatridecafulvalene 12, 6,8-bisdehydro-4,5:10,11-dibenzopentatridecafulvalene 13, 5,10-dimethyl-6,8-bisdehydropentapentadecafulvalene 14, 7,12-dimethyl-8,10-bisdehydropentaheptadecafulvalene 15, and 7,12-dimethyl-8,10-bisdehy-dropentanonadecafulvalene 16 were synthesized through the reaction of the corresponding bisdehydroannulenones 1–6 with cyclopentadienide. The tropic nature of these pentafulvalenes is discussed on the basis of 1H NMR and electronic spectra as well as those of the corresponding heptafulvalene derivatives.
NMR and XPS Studies of Some Diselenocarbamates. Bond Switch in Bis(dimethylselenocarbamoyl) Triselenide
Authors: Kobayashi Keiji , Tukada Hideyuki , Kikuchi Koichi , Ikemoto Isao
Published: July 2006

The hindered rotation about the C–N bond in dimethyldiselenocarbamates Me2N–CSe–SeR has been investigated by variable temperature NMR spectroscopy. The barrier to the rotation was almost independent of the partial structure of R (R=–Me, –CSe–NMe2), being 19 kcal mol−1* at around 93 °C. However, for bis(dimethylselenocarbamoyl) triselenide (R=–Se–Se–CSe–NMe2) (1), no splitting of N-methyl signals was observed in the 1H and 13C NMR spectra at subambient temperature. The equivalence of the methyl groups is discussed in terms of the bond switch between C=Se and C–Se moieties. The existence of the bond switch in 1 was also suggested by the XPS studies; the binding energy of the four selenium atoms was found to lie between those of C=Se and –Se–types of the selenium atoms, indicating that 1 takes an intramolecular coordination structure rather than a linear triselenide structure in the solid state, thereby facilitates the bond switch in solution.
The Determination of a Small Amount of a Biological Constituent by the Use of Chemiluminescence. VI. The Flow-Injection Analysis of Protein Using a 1,10-Phenanthroline–Hydrogen Peroxide System
Authors: Hara Tadashi , Ebuchi Takashi , Arai Akihiro , Imaki Masakatsu
Published: July 2006

Since the catalytic activity of copper(II) for the chemiluminescent reaction between 1,10-phenanthroline and hydrogen peroxide decreased in the presence of protein, this phenomenon was applied to the determination of protein. The determination of protein was carried out by a flow-injection method, and the conditions for the determination of protein were established. The catalytic activity of copper(II) was enhanced by using an amino acid instead of the conventional biuret reagent. Similar calibration curves were obtained for human serum albumin, bovine serum albumin, human serum γ-globulin, bovine serum γ-globulin, and ovalbumin. According to the present flow-injection method using a chemiluminescent reaction, a small amount of protein could be conveniently and economically determined over a wide range of concentrations, 5.0×10−6 g dm−3–1.0×10−1 g dm−3 at the rate of about 20 samples per hour, with the detection limit of 250 pg as the injected amount and the coefficient of variation of 5.9% (n=9). The sensitivity of the present method was about 40 times that of the previous luminol-hydrogen peroxide system.
Synthesis of Gramicidin S (GS) Analogs, [3–4-δAva]–GS and [3–4,3′–4′-Bis(δAva)]–GS (δAVa=5-Aminovaleric Acid)
Authors: Sofuku Shosuke , Sugiyama Yasutaro , Muramatsu Ichiro
Published: July 2006

Gramicidin S (GS) analogs, [δAva3–4]–GS and [δAva3–4,3′–4′]–GS, were synthesized. Both of these peptides are analogs in which one or two l-leucyl-d-phenylalanyl residues of GS are replaced by one or two 5-aminovaleric acid residues. The CD spectrum of the mono-substituted analog has two troughs as that of GS. However, this analog showed almost no antimicrobial activity. Moreover, the di-substituted analog showed a CD spectrum that is ascribed to a random structure and had no antimicrobial activity.
Reaction of Reduced PQQ (PQQH2) and Molecular Oxygen
Authors: Itoh Shinobu , Ohshiro Yoshiki , Agawa Toshio
Published: July 2006

Reduced PQQ (PQQH2) is prepared by the reaction of PQQ with thiophenol, 1-benzyl-1,4-dihydronicotinamide (BNAH), sodium dithionite, or sodium borohydride. Oxidation of PQQH2 to PQQ by molecular oxygen in aqueous solutions is investigated kinetically. The oxidation is accelerated gradually with proceeding of the reaction, which may be attributed to the side reaction of PQQH2 and H2O2 produced by the reaction of PQQH2 and O2. As in fact, the yield of H2O2 is found to be 50% based on PQQH2. Initial rate is first-order in oxygen concentration. The pH-rate profile suggests that an active species in the reaction is PQQH−. Autocatalysis of O2\ewdot and PQQ itself is scarcely detected in this reaction. The mechanism of the oxidation is also discussed.
Motions of Tetramethylammonium Cations and Phase Transitions in Solid [(CH3)4N]2CdX4 (X=Cl, Br, I) as Studied by 1H NMR, Powder X-Ray Diffraction, and Differential Thermal Analysis Measurements
Authors: Sato Setsuko , Ikeda Ryuichi , Nakamura Daiyu
Published: July 2006

The temperature dependences of 1H spin-lattice relaxation times were determined at 20 MHz for [(CH3)4N]2CdCl4, [(CH3)4N]2CdBr4, and [(CH3)4N]2CdI4. For the last two complexes, the frequency dependence of the relaxation time was observed above room temperature. 1H NMR second moments were observed for the bromide complex. At room temperature, the first two complexes were found to be isomorphous with the iodide complex which forms orthorhombic crystals. Differential thermal analysis experiments revealed that these complexes undergo four, one, and one solid-solid phase transitions in the above order between ca. 80 and 430 K. Two 1H T1 minima were clearly observed at lower temperatures for the chloride and bromide complexes, whereas at least three 1H T1 minima partly overlapped with each other were detected at lower temperatures for the iodide complex. For the former two complexes, the 1H T1 data were well analyzed by the general method already reported. For the bromide and iodide complexes, 1H T1 curves observed showed a maximum above room temperature. Motions of the cation activated in these complexes are discussed in relation to the crystal field experienced by the cation.
Preparations, NMR Spectra, and Electrochemical Properties of a (Ferrocenylcarbonyl)palladium(II) Complex and Its Derivatives with Some Chelate Groups Attached via Two Ligating Nitrogen Atoms
Authors: Onishi Masayoshi , Hiraki Katsuma , Konda Hatsumi , Ishida Yasuhiro , Ohama Yushichiro , Uchibori Yuko
Published: July 2006

Oxidative addition of (chloroformyl)ferrocene to [Pd(PPh3)4] yielded a stable acylpalladium(II) compound of [Pd(COFc)Cl(PPh3)2] (1), (Fc=ferrocenyl). Complex 1 was treated with alkali metal salts of poly(1-pyrazolyl)borates (HnBPz4−n), (Pz=1-pyrazolyl) to give complexes [Pd(COFc)(HnBPz4−n)(PPh3)], (2, n=0; 3, n=1; and 4, n=2), which retained the palladium-attached ferrocenylcarbonyl structure. Reaction of 1 with 1,10-phenanthroline (phen) afforded [Pd(COFc)Cl(phen)], whereas reaction with 2,2′-bipyridine gave [{Pd(COFc)Cl(PPh3)}2] as an isolable material. Transformation of the ferrocenylcarbonyl moiety took place to the ferrocenyl group on palladium, in chlorine-abstraction from 1 with AgClO4·H2O in CH3CN. In the temperature-dependent 1H-NMR spectra, fluxional behavior was observed for the poly(1-pyrazolyl)borate groups in 2 and 3. Electrochemical experiments were carried out for 1–4 in CH3CN using platinum working electrodes, and reversible one-electron redox-couples were detected, which were attributed to the process Fe(II)\ightleftarrowsFe(III) in the ferrocenyl moiety. Furthermore, electron-withdrawing effects of the [poly(1-pyrazolyl)borato]palladiocarbonyl moieties from the Fe centers were compared among these complexes, in relation to their redox potentials.
Stereospecific Synthesis of the Fungal Prohormone (±)-Trisporol B via the Palladium-Catalyzed Cross-Coupling Reaction of 1-Alkenylborane with 1-Haloalkene
Authors: Miyaura Norio , Satoh Yoshitaka , Hara Shoji , Suzuki Akira
Published: July 2006

The synthesis of the titled C18 apocarotenoid prohormone by means of palladium-catalyzed cross-coupling reaction between (E)-1-alkenylbis(1,2-dimethylpropyl)-borane (10) and (Z)-6-iodo-5-hepten-2-one ethylene acetal (9) is described. The reaction is highly stereoselective and the demanded (7E) and (9Z) double bonds are readily introduced.
Coupling Reaction of Grignard Reagents with α,ω-Dibromoalkanes in the Presence of Copper(I) Bromide-HMPA:Preparation of α,ω-Bis(vinylaryl)alkanes
Authors: Nishimura Jun , Yamada Noriyuki , Horiuchi Yuzuru , Ueda Eiji , Ohbayashi Akihiro , Oku Akira
Published: July 2006

The coupling reaction of Grignard reagents with α,β-dibromoalkanes took place smoothly in THF/ HMPA (12:1) in the presence of a catalytic amount of copper(I) bromide and gave the products in 60–100% yields. Several α,ω-bis(vinylaryl)alkanes were prepared in reasonable yields by the application of this reaction.
Crystal Structures of 8-Oxa-6-azabicyclo[3.2.1]octan-7-one and the 4(e)-Bromo-substituted Derivative
Authors: Gu Yuanxin , Yamane Takashi , Ashida Tamaichi , Hashimoto Kazuhiko , Sumitomo Hiroshi
Published: July 2006

The crystal structures of the bicyclic oxalactam, 8-oxa-6-azabicyclo[3.2.1]octan-7-one(BOL) and the 4(e)-bromo-substituted derivative(Br–BOL) were determined by the X-ray diffraction method. Crystal data: (BOL) P212121, a=10.926(3), b=9.115(2), c=6.280(2), Å, Z=4; (Br–BOL) P212121, a=10.708(3), b=11.053(3), c=6.208(2), Å, Z=4. Refinements were carried out by the full-matrix least-squares method. R values are; (BOL) 0.050 for 601 reflections, (Br–BOL) 0.028 for 866 reflections. Both structures are quite similar to each other. The packing scheme of BOL is essentially the same as that of Br–BOL. Molecules are linked by N–H···O hydrogen bonds around a two-fold screw axis, giving rise to infinite chains extended along the c axis.
The Synthesis of Dibenzo-Annelated Annulenes Using Reductive Coupling. Bisdehydrodibenzo[14]-, -[16]-, -[18]-, -[20]-, and -[22]annulene
Authors: Ojima J\={u}ro , Yamamoto Koji , Kato Tadahito , Wada Kazuyo , Yoneyama Yoshiharu , Ejiri Emiko
Published: July 2006

Bisdehydrodibenzo[14]-, -[16]-, -[18]-, -[20]-, and -[22]annulene were synthesized by intramolecular reductive couplings using a low-valent titanium reagent. These bisdehydrodibenzo-annulenes proved to be atropic from an examination of the 1H NMR spectra.
Active Carbon-Supported Copper(I) Chloride as Solid Adsorbent for Carbon Monoxide
Authors: Hirai Hidefumi , Wada Keiichiro , Komiyama Makoto
Published: July 2006

An active carbon-supported copper(I) chloride (CuCl) is prepared by stirring active carbon in aqueous hydrochloric acid solution of CuCl, followed by removal of the liquid phase under 6 mmHg at 100 °C. The resulting solid rapidly adsorbs carbon monoxide (CO) at 20 °C from 9:1 CO–N2 mixture under 1 atm (the CO partial pressure 0.9 atm) and the equilibrium molar ratio of adsorbed CO to CuCl is 0.88. All of adsorbed CO is promptly desorbed either by reducing CO partial pressure to 0.4 mmHg at 20 °C or by elevating temperature from 20 °C to 120 °C under 1 atm (the CO partial pressure 0.9 atm). Reversible adsorption-desorption cycles are repeated four times without measurable decrease in the adsorbing capacity. The adsorbing capacity of the active carbon-supported CuCl is much larger than either that of CuCl solid or that of active carbon. Effective CO adsorption by the present adsorbent is attributed to formation of complex between CO and CuCl, which is highly dispersed on the surface of active carbon.
Reactivity of Electrons Produced in Gamma-Irradiated Zeolite Toward Several Electron Scavengers
Authors: Nakazato Chiyoko , Masuda Takahiro
Published: July 2006

Relative rates of reaction of electrons produced in gamma-irradiated zeolite (Molecular Sieve 13X) with several electron scavengers were determined by competition kinetics using dinitrogen monoxide as a reference compound. A part of the electrons produced in irradiated zeolite have been disclosed to be quasi-free from the feature of their reactivity toward electron scavengers that the reactivity is similar to that of quasi-free electrons found in irradiated liquid 2,2-dimethylpropane. An analysis based on competition kinetics has provided a value 9.8×1012 dm3 mol−1 s−1 as the lower limit on the rate constant for the reaction of quasi-free electrons with positive holes produced in irradiated zeolite.
An EXAFS Investigation of the Coordination Structure of Copper(II) Ions in Aqueous Cu(ClO4)2 and Methanolic CuCl2 Solutions
Authors: Tajiri Yoshichika , Wakita Hisanobu
Published: July 2006

The coordination structure of copper(II) ions in aqueous and methanolic solutions was investigated by means of EXAFS spectroscopy. The hexaaquacopper(II) complex in the aqueous Cu(ClO4)2 solution had an elongated octahedral structure, with four equatorial distances of 2.00 Å and two axial distances of 2.28 Å. Scarcely no axial interaction has been seen in the radial-distribution curve after the Fourier transform of the EXAFS spectrum, for the real and imaginary parts of the Fourier transformed function for the axial interactions are diminished by the interference of those for the equatorial interactions. Two distances for the equatorial interactions of the mixed-ligand chlorocopper(II) complexes in the methanolic CuCl2 solution were clearly resolvable in the radial-distribution curve; they were 2.00 Å and 2.22 Å for the Cu–O and Cu–Cl interactions respectively.
Synthetic Study on Peptide Antibiotic Nisin. II. The Synthesis of Ring B
Authors: Fukase Koichi , Wakamiya Tateaki , Shiba Tetsuo
Published: July 2006

Synthesis of a cyclic sulfide moiety ring B in peptide antibiotic nisin was successfully achieved by desulfurization from a corresponding disulfide peptide with tris(diethylamino)phosphine. The configuration on β-carbon atom of threo-3-methyl-d-cysteineresidue in the disulfide peptide was retained through the reaction to give a desired natural threo form of methyllanthionine.
Synthesis of Kaolinite-Lactam Intercalation Compounds
Authors: Sugahara Yoshiyuki , Kitano Shuichi , Satokawa Shigeo , Kuroda Kazuyuki , Kato Chuzo
Published: July 2006

Intercalation compounds of kaolinite with 2-pyrrolidone and 2-piperidone have been prepared for the first time by displacing other intercalates. 2-Pyrrolidone expanded the lattice of kaolinite to 11.9 Å, while d001 of 12.7 Å was observed with the kaolinite–2-piperidone intercalation compound. Their IR spectra indicated the formation of a hydrogen bond between the C=O of the lactams and the OH of kaolinite. Nevertheless, their interactions were different between these two intercalation compounds. By a comparison of their behaviors, it has been concluded that the kaolinite–2-pyrrolidone intercalation compound is thermally more stable than the kaolinite–2-piperidone intercalation compound.
Temperature Dependence of 35Cl Nuclear Quadrupole Resonance Frequencies and Hydrogen Bonding in Some Metal(II) Hexachlorostannate(IV) Hexahydrates
Authors: Horiuchi Keizo , Sasane Akinobu , Mori Yoshihiro , Asaji Tetsuo , Nakamura Daiyu
Published: July 2006

The temperature dependences of 35Cl NQR frequencies were observed over a fairly wide range of temperature for MSnCl6·6H2O [M(II)=Mg, Ca, Mn, Co, Ni] forming isomorphous crystals (R\bar3) at room temperature. These complexes yielded unusual 35Cl NQR temperature dependence curves showing a positive temperature coefficient. This can be attributed to the existence of Cl···H–O type weak hydrogen bonds.
The Structure of Liquid N-Methylformamide by Means of X-Ray Diffraction and Ab Initio LCGO–MO–SCF Calculations
Authors: Ohtaki Hitoshi , Itoh Sumiko , Rode Bernd M
Published: July 2006

The liquid structure of N-methylformamide (NMF) has been investigated by the X-ray diffraction method and the ab initio MO-SCF method. The structure parameters within a molecule were obtained as follows: C=O : 122(1) pm, C(methyl)–N : 145(2) pm, C(carbonyl)–N : 134(2) pm, N···O : 222(4) pm, C(methyl)···O : 278(6) pm. The intermolecular hydrogen–bonded N···O distance was estimated to be 298(11) pm. A linear and flexible chain structure was proposed for the liquid structure of NMF on the basis of scattered intensity data by the X-ray diffraction method and of interaction energies and geometries of hydrogen-bonded NMF molecules calculated by the ab initio MO calculations.
Proton Transfer Reactions in the Triplet State of Benzophenone Studied by Nanosecond Laser Flash Photolysis
Authors: Hoshi Masahiko , Shizuka Haruo
Published: July 2006

Proton-transfer reactions in the triplet state of benzophenone in H2O–acetonitrile (4:1) at 20 °C have been studied by means of nanosecond nitrogen laser flash photolysis at 337 nm. The proton association (k1) and dissociation (k2) rates are determined to be 5.0 (±0.5)×109 mol−1 dm3 s−1 and 3.3 (±0.3)×109 s−1 respectively by a transient kinetic treatment. These rates are large enough to make an acid-base equilibrium during the lifetime of the triplet state. The acidity constants (pKa*) in the triplet state of benzophenone obtained by the transient kinetic treatment, the Ware plot, and the Tn←T1 absorbance titration curve are the same [0.18 (±0.1)]. The pKa* value determined by the titration method is appreciably dependent upon the delay time after the start of pulsing (the accurate value was obtained at the delay time 20 ns). There is no proton-induced quenching in the triplet state of benzophenone, since electrophilic protonation occurs at the oxygen atom in the carbonyl group. The reactive state for protonation in the triplet state is not 3(n,π*), but 3(π,π*), judging from the large k1 value and the pKa* value.
Electrocatalytic Oxygen Reduction at (Tetrasulfonatophthalocyaninato)cobalt Incorporated Polypyrrole Film Electrode
Authors: Osaka Tetsuya , Naoi Katsuhiko , Hirabayashi Takayuki , Nakamura Sadako
Published: July 2006

Electrocatalytic activity of oxygen reduction was strikingly improved at a GC(glassy carbon)/PPy(polypyrrole)/CoTSP((tetrasulfonatophthalocyaninato)cobalt) electrode among the other CoTSP doped polymer electrodes. The GC/PPy/CoTSP electrode was formed by electro-oxidized polymerization of pyrrole on a glassy carbon(GC) electrode in methanol solution containing CoTSP. The catalytic oxygen reduction at the GC/PPy/CoTSP electrode was mainly analyzed with RRDE technique. Oxygen reduction reaction at the GC/PPy/CoTSP electrode in 0.05 mol dm−3 H2SO4 showed ca. 0.5 V more anodic onset potential than the value obtained with a GC electrode in 0.05 mol dm−3 H2SO4 containing 10−3 mol dm−3 CoTSP. Kouteckty-Levich plot, i.e., the relation between Ilim−1 and ω−1⁄2 for the GC/PPy/CoTSP electrode gave almost the same slope of theoretical four-electron reduction at the limiting current region. It was indicated that the apparent oxygen reduction is occurred through direct four-electron exchange process. On the other hand, the GC electrode in dissolved CoTSP gave almost the same slope as of theoretical two-electron reduction. A diagnostic criterion for oxygen reduction proposed by Wroblowa et al. indicated that the parallel pathways of two- and four-electron reduction exist for the GC/PPy/CoTSP electrode.
Synthesis and Electrical Conductivity of a New Family of Pt Mixed Valence Complexes: Pt6(NH3)14Cl10X4 (X=ClO4, BF4, and PF6)
Authors: Tanaka Masako , Tsujikawa Ikuji
Published: July 2006

A new family of Pt mixed valence complexes: Pt6(NH3)14Cl10X4 (X=ClO4, BF4, and PF6) was synthesized from the Magnus green salt (MGS) by the partial oxidation using an oxidant of H2O2 or by electrochemical method. On partial oxidation, the 1/6 of Cl− ligands in MGS are randomly replaced by NH3 ligands and simultaneously counter ions X are introduced. These complexes comprise of one-dimensional chains with direct contact between Pt atoms and consequently a quasi-one-dimensional band made up of 5dz2 orbital of Pt is formed. The average valence of Pt is +2.33 and the distance between Pt atoms along a chain is shorter than or comparable to that of K2[Pt(CN)4]Br0.3·xH2O (KCP). The electrical conductivity σ of these complexes was measured from 80 K to r.t. The σ(r.t.) is rather high in spite of the measurement on the powder pressed pellets. This suggests that σ along a chain direction may be as high as that of KCP if single crystals can be obtained. The conductivity data were fitted using a gap energy with various temperature dependence. In the complex with X=PF6, there may be a phase transition caused by ordering of PF6− ions at about 110 K.
Synthesis and Photolysis of Tricyclo[5.3.1.02,6]undeca-3,9-dien-8-ones and -4,9-dien-8-ones. Formation of Novel Trishomocubanones
Authors: Ogino Toshio , Awano Kazuyuki
Published: July 2006

A series of 10-substituted tricyclo[5.3.1.02,6]undeca-3,9-dien-8-ones (6) and the 4,9-dien-8-one isomers (7) were synthesized and photolyzed. Upon irradation, whereas most of the derivatives underwent [2+2] photocyclization to give the corresponding novel trishomocubanones, the methyl and phenyl derivatives of 7 afforded products attributable to intramolecular hydrogen abstraction by the β-carbon of the α,β-unsaturated ketone along with the photocyclization products.
Activation Analysis of Oxygen in SnO2 and Zn2SnO4 Crystals
Authors: Yoshida Ryoichi , Hasegawa Yoshihisa , Yamai Iwao , Kodaira Kohei , Matsushita Toru
Published: July 2006

Oxygen content of SnO2 and Zn2SnO4 crystals grown by the vapor phase method was determined by 14 MeV neutron activation analysis. The oxygen contents in the crystals were a little smaller than the theoretical values. The oxygen deficiency in the crystals was found to be related to their inherent semiconductive properties and density.
Insertion of Benzyne and Substituted Benzynes into the S–S Bond of Diphenyl and Di-p-tolyl Disulfides Yielding the Corresponding o-Bis(arylthio)benzenes
Authors: Nakayama Juzo , Tajiri Takayuki , Hoshino Masamatsu
Published: July 2006

Benzyne and substituted benzynes undergo insertion into the S–S bond of diphenyl and di-p-tolyl disulfides to afford the corresponding o-bis(arylthio)benzenes in low but reproducible yields.
The Microwave Spectrum of (Z)-(Propionaldehyde Oxime)
Authors: Katayama Makoto , Sakaizumi Takeshi , Yamaguchi Ichiro , Ohashi Osamu
Published: July 2006

The microwave spectrum of (Z)-(propionaldehyde oxime) was observed in the frequency region of 10 to 30 GHz. The rotational constants (MHz) for the ground vibrational state were determined to be A=15453.95±0.20, B=2733.60±0.03, and C=2394.85±0.02. The conformation has been plausibly deduced to be the ap, Z-form from the rotational constants. The dipole moments were determined by the Stark effect: μa=0.889±0.010 and μb=0.364±0.025 D.
Tris(tellurato)cobaltate(III) and Tris(ethylenediamine)tris(tellurato)tetracobaltate(III) Complexes
Authors: Shimura Yoichi , Hosokawa Yutaka
Published: July 2006

Alkali metal salts of two new telluratocobaltate(III) complexes, [Co(TeO6H4)3]3− and [Co4Te3O18(en)3]6−, have been prepared. The latter heteropoly type complex and the related periodate analogue [Co4I3O18(en)3]3− have been optically resolved.
Diode Laser Spectrum of the ν8 Band of CH3SH
Authors: Nakagawa Kuniaki , Kojima Takeshi , Hirota Eizi
Published: July 2006

The Stark effect was used to assign four series of the transitions in the heavily perturbed spectrum of methanethiol in the 14 μm region: K=0 and two K=1 series of A torsional symmetry and K=0 series of E symmetry. Effective parameters were determined for each series. The K=0 levels of A symmetry in the ν8 state were found to be perturbed by a Fermi-type resonance.
ESR Study of Glass-Like Carbons
Authors: Kawamura Kazuro , Kimura Shiushichi
Published: July 2006

ESR studies were carried out on a variety of glass-like carbons made from different precursors heat-treated in the range 300–2500 °C. It was found that the behaviors of unpaired electrons were nearly identical. The temperature dependence of ESR spectrum showed that the behavior of localized unpaired electrons in the glass-like carbons changed to that of delocalized ones at HTT about 2500 °C. The ESR spectrum of the glass-like carbons heat-treated at 800 °C consisted of a single line under a pressure of above 10−4 Torr but split into two components when air was admitted. This strong interaction with unpaired electrons and air (oxygen molecules) is caused by the active structure related to micropores in the glass-like carbons. We suppose that the polyene type radicals are the most suitable as the active structure to interpret the behavior of unpaired electrons in glass-like carbons heat-treated at 800 °C. As another major point in this study, it was found that there is a correlation between unpaired electron concentration and the g value.
Solid-State NMR Studies on Pillar-Interlayered Naturally-Occurring Montmorillonite
Authors: Matsumoto Mutsuyoshi , Suzuki Minoru , Takahashi Hiroshi , Saito Yasukazu
Published: July 2006

Solid-state MAS NMR spectroscopy on naturally occurring montmorillonite has revealed that the Fe(III), contained in the octahedral layer, exerts a greater influence on octahedral Al nuclei than on tetrahedral ones. The same trend is observed in a more pronounced manner with the material intercalated with [AlO4Al12(OH)24(OH2)12]7+ cations. Mechanisms of selective peak broadening in solidstate NMR spectra are discussed.
Metal Complexes of Amino Acids. XV. Racemization and Deuteration of Bis(biguanide)sarcosinatocobalt(III) Complex
Authors: Kawaguchi Hiroshi , Matsuki Mizuki , Ama Tomoharu , Yasui Takaji
Published: July 2006

All four possible optical isomers (Δ(S), Δ(R), Λ(S), and Λ(R)) of the bis(biguanide)sarcosinatocobalt(III) ion, [Co(sar)(Hbg)2]2+, were isolated and characterized by their absorption, CD, and 1H NMR spectra. The optically active [Co(sar)(Hbg)2]2+ ion in a basic aqueous solution showed a loss of CD intensity due to racemizations at both the chiral cobalt center (Δ\ightleftarrowsΛ) and the asymmetric nitrogen center (R\ightleftarrowsS). The rate of an R\ightleftarrowsS change was ca. 50 times slower than that of a Δ\ightleftarrowsΛ change. The rate of deuteration (H→D) at the asymmetric nitrogen atom was slower than those of other sarcosinato complexes. The ratio kH–D/kinv was about 102–103. The rates of racemization (Δ\ightleftarrowsΛ) for the [Co(amino acidato)(Hbg)2]2+ ion series increased in the order l-valine<l-alanine<glycine<sarcosine.
X-Ray Structure of 5-Chloro-1-thia-5-boracyclooctane
Authors: Furusaki Akio , Weike Zhou , Suzuki Akira
Published: July 2006

5-Chloro-1-thia-5-boracyclooctane has been prepared by the hydroboration of diallyl sulfide with a chloroborane–dimethyl sulfide complex and its structure containing a sulfur–boron dative bond has been examined in detail by an X-ray crystallographic analysis.
Reaction of α,β-Unsaturated Carboxylic Acids with Manganese(III) Acetate in the Presence of Chloride Ion
Authors: Yonemura Hiroshi , Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

The reaction of 3-phenylpropenoic acids with manganese(III) acetate–Cl− complex yielded 1,2,2-trichloro-1-phenylethanes, 1-acetoxy-2,2-dichloro-1-phenylethanes, and 2,2-dichloro-1-phenylethanols. (E)-2,3-Diphenylpropenoic acids gave 2,2-dichloro-1,2-diphenylethanones and 2-acetoxy-1,2-diphenylethanones. 3,3-Diphenylpropenoic acids yielded 2,2-dichloro-1,1-diphenylethenes, 1-acetoxy-2,2-dichloro-1,1-diphenylethanes, 2,2-dichloro-1,1-diphenyl-1-ethanols, and 2-hydroxy-2,2-diphenylethanal. Fluorenylideneacetic acid gave 9-chloro-9-(dichloromethyl)fluorene, 9-acetoxy-9-(dichloromethyl)fluorene, and 9-fluorenone. 1-Cyclohexenecarboxylic acid yielded 1,2-dichlorocyclohexanecarboxylic acid and 1-acetoxy-2-chlorocyclohexanecarboxylic acid. The reaction can be explained in terms of a free-radical mechanism involving manganese(III) acetate–Cl− complexation, addition of Cl− radical, decarboxylation, and the oxidation of chloroethenes which are the reaction intermediates.
A Positive Halogen Mediated Ring-Opening Reaction of 2-(α-Phenylthiobenzyl)cycloalkanol Derivatives
Authors: Yasumura Masateru , Takaki Ken , Tamura Takao , Negoro Kenji
Published: July 2006

A new ring-opening reaction of the title cycloalkanols (1 and 3) takes place upon treatment with N-chloro-succinimide and triethylamine to give ω-oxo α,β-unsaturated sulfides (2) in fairly good yields.
Thermal Dimerization of 10-Methyleneanthrone
Authors: Hirakawa Kiyoichi , Ogiue Eriko , Motoyoshiya Jiro , Kakurai Toshio
Published: July 2006

The thermal reaction of the title compound (1) gave three dimeric products which were formed via a path involving two competitive reactions, Diels-Alder and radical dimerization.
Solvent Extraction Separation of Germanium with Aliquat 336S from Citric Acid Solutions
Authors: Vibhute Chandrashekhar P , Khopkar Shripad M
Published: July 2006

Germanium was quantitatively extracted with 0.1 mol dm−3 Aliquat 336S in xylene from 1×10−3 mol dm−3 citric acid solution adjusted to pH 3.5. It was stripped with 0.5 mol dm−3 hydrochloric acid and determined spectrophotometrically at 530 nm as the complex with phenylfluorone. It was effectively separated from binary as well as ternary mixtures by taking advantage of the difference in the stability of the citrate complexes with metal ions in mineral acids. The method was applied to the determination of germanium in coal fly ash.
Removal of Some Alkali Salts from Aqueous Solution by Active-Charcoal Electrode
Authors: Ichinose Masao , Yasuoka Takashi , Mitsuzawa Shunmei , Sasaki Tsunetaka
Published: July 2006

An electrolytic removal of potassium and sodium sulfates from aqueous solutions was worked out by using an active-charcoal cathode and a platinum anode with a porous porcelain septum between them. Maximum removal of nearly 99% was attained for these salts. The mechanism of removal was confirmed to be based on the facts that potassium and sodium ions are entrapped and concentrated as hydroxides in the pores of the active-charcoal cathode while sulfate ions are removed from the solution and concentrated as sulfuric acid in the anode chamber.
Theoretical Studies on the Catalytic Oxidation of Carbon Monoxide on Nickel Clusters
Authors: Srivastava A K , Kojima Isao , Miyazaki Eizo
Published: July 2006

Complete neglect of differential overlap (CNDO) molecular orbital calculations using the method of Anno and Sakai for the evaluation of the valence orbital ionization potential (VOIP) were performed with the aim of studying the oxidation of carbon monoxide on nickel clusters. A cluster surface was assumed to be preadsorbed with oxygen and the variation of various bond energies with the approach of a carbon monoxide molecule was studied for different models. Various possibilities for the reaction path are discussed in the light of the theoretical findings and it is suggested that at a low coverage of oxygen the reaction may follow a Langmuir–Hinshelwood path, whereas at a high coverage, an Eley–Rideal path might be more probable.
Reaction of Tri-n-butyltin ω-Haloalkoxide (n-Bu3SnO(CH2)nX) with Isothiocyanate
Authors: Baba Akio , Shibata Ikuya , Kashiwagi Hiroki , Matsuda Haruo
Published: July 2006

Tri-n-butyltin ω-haloalkoxides are useful reagents for the preparation of sulfur-containing five and six-membered cyclic compounds combined with isothiocyanates.
Pretreatments of Porous Silica for Improving the Activity of a Nickel-Loaded Catalyst
Authors: Arai Masahiko , Ikushima Yutaka , Nishiyama Yoshiyuki
Published: July 2006

Nickel catalysts supported on porous silicas treated with water, ethanol, and 1-butanol were found to be more active than that supported on untreated silica for ethane hydrogenolysis and furan hydrogenation. To elucidate the reason for the activation, some surface properties of the treated silicas were examined. The treatments decreased the surface area and increased the volume of the macropores, the surface density of hydroxyl groups, and the heat of immersion in water per unit surface area. The state of nickel on the support was examined by temperature programed desorption(TPD) of hydrogen, X-ray diffraction(XRD), and scanning electron microscopy/X-ray microanalysis. The dispersion measured by XRD was not appreciably altered by the treatments, but the TPD snowed more hydrogen desorbed above 150 °C from nickel on the treated supports. The activation of nickel by pretreatment of the support was ascribed to the increase of those nickel atoms which dispersed finely over the support by the increased number of surface hydroxyl groups. This was based on the number of hydroxyl groups per unit surface area. The nickel catalyst supported on the pretreated silicas showed greater thermal stability.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. X. Rates of Dissociation of the C–N Bond in Substituted 1-(1,3-Dithiolan-2-yl)pyridinium Perchlorates
Authors: Morita Toshiari , Oki Michinori
Published: July 2006

Rates of dissociation of the C–N bond in substituted 1-(1,3-dithiolan-2-yl)pyridinium ions in the perchlorate forms were obtained by the dynamic NMR technique in nitromethane-d3 and for one case in acetonitrile-d3. The study of the substituent effects on the rates of dissociation revealed that the rates were linearly correlated with the pKa values of the substituted pyridines. The mechanism of the dissociation was postulated to be of SN2 type, the perchlorate ion acting as a nucleophile, from the kinetic data.
Stereoselective Cycloadditions of Pyridinium or Isoquinolinium Methylides with Olefinic Dipolarophiles and Subsequent Cycloadditions of the Cycloadducts with Nitrile Oxides
Authors: Tsuge Otohiko , Kanemasa Shuji , Takenaka Shigeori
Published: July 2006

Pyridinium or isoquinolinium methylides undergo highly stereo- and regioselective cycloadditions with olefinic dipolarophiles to form unstable tetrahydroindolizine derivatives. One of the two double bonds existing in the dihydro heteroaromatic ring of the cycloadducts reacts with nitrile oxides, in the same flask, in stereo-, regio-, and periselective fashions to lead to stable isoxazole-fused tetrahydroindolizines in good yields.
Nonexistence of Hydration Number Change of Cd2+ Ions in Aqueous Cd(NO3)2 Solution
Authors: Kanno Hitoshi
Published: July 2006

Raman spectra for the Cd2+–OH2 stretching vibration (ν1 band) were measured for aqueous Cd(NO3)2 solutions of R=15 and 40 (R: moles of water/moles of salt). Contrary to the results reported by Kuznetsov et al., it is concluded that the hydration number of Cd2+ ions does not change with salt concentration in the Cd(NO3)2 solution.
Solvent Effects on the Unimolecular Dissociation of Radical Anions Studied by Pulse Radiolysis
Authors: Kimura Norio , Takamuku Setsuo
Published: July 2006

The rate constants of the unimolecular dissociation of radical anions formed by one-electron reduction of chloroacetophenone isomers in dipolar aprotic solvents were measured by a pulse radiolysis technique. The reactivities of these isomers were affected by the polarity of the solvent used.
Stabilities of the Copper(II) Complexes with Quadridentate Derivatives of l-Prolinamide and l-Proline Methylamide
Authors: Murakami Tasuku , Chiba Koichi
Published: July 2006

The stability constants of the copper(II) complexes with potentially quadridentate derivatives of l-prolinamide and l-proline methylamide (see text) have been determined by potentiometric titrations. The amide-proton dissociations from the complexes have also been estimated. These were then discussed in terms of the ligand structure and the complex geometry.
Temperature-Programmed Desorption of Ammonia on Zeolites. Influence of the Experimental Conditions on the Acidity Measurement
Authors: Niwa Miki , Iwamoto Masakazu , Segawa Koh-ichi
Published: July 2006

The Influence of the experimental conditions of the TPD (Temperature-Programmed Desorption) of ammonia on the measurement of acidity of mordenites and Y zeolites was studied. The results were applicable to the measurements of the strength and the number of acid sites of zeolites. For contact times of the carrier gas from 10−2 to 10−6 g min ml−1 defined as W/F (W, sample weight; F, flow rate of the carrier gas), the peak maximum temperature was related to the parameter (W/F). The relationship was explained on the basis of a theoretical equation derived by Cvetanovic and Amenomiya under the conditions of readsorption. Ammonia is readsorbed on zeolites under these conditions, and one has to use the experimental conditions of the same contact time in order to evaluate the acid strength of zeolite from the peak maximum temperature. On the other hand, the ratio of intensity of low temperature peak (1-peak) to that of the high temperature peak (h-peak) increased with increasing the contact time of the carrier gas. This relation suggested that the 1-peak intensity depended upon the degree of evacuation of the weakly-held ammonia. The 1-peak is ascribable to very weakly or physically adsorbed ammonia on zeolites, and only the h-peak has to be accounted for to measure the number of acid sites.
The Solvent Extraction of Alkaline Earth Metal Ions with Nonionic Surfactants
Authors: Sakai Yukio , Nakamura Hiroshi , Takagi Makoto , Ueno Keihei
Published: July 2006

The extraction of alkaline earth metal ions has been investigated using a mixture of polyethylene glycol mono-p-nonylphenyl ether (PEGP; average number of oxyethylene group, 10) and 4-(1,1-dimethyl-3,3-dimethylbutyl)-2,5-dinitrophenol (2,5-dinitro-4-t-octylphenol, DNP; HL) in 1,2-dichloroethane. The metal extraction takes place with one molecule of deprotonated DNP (L−) and an extraneous monoanion (X−) for neutralization of the dicationic charge of the metal ion. The ease of extraction generally follows the order, Ba2+>Sr2+>Ca2+>>Mg2+. The nature of the anion present in the aqueous phase strongly affects the extractability. For barium, the extractability decreases in the order ClO4−>SCN−>I−>Cl−>NO3−. The composition of the extracted complexes for barium and strontium ions proportional to the metal is metal : PEGP : L− : X−=1 : 1 : 1 : 1. The overall extraction constants were estimated.
Solvent Extraction of Copper(II) with Lipoic Acid in Benzene. Evidence for the Preferential Coordination of Carboxylate
Authors: Yamada Hiromichi , Okuda Toshiyuki , Fujii Yukio , Mizuta Masateru , Tanaka Motoharu
Published: July 2006

The extraction of copper(II) was carried out with lipoic acid in benzene at 25 °C and at a constant ionic strength in the aqueous phase: 0.1 mol dm−3 (NaNO3). The partition constant, KD,HA of lipoic acid between benzene and water, and the dimerization constant, K2,HA of lipoic acid in benzene were determined: logKD,HA=1.17 and logK2,HA=2.51 The dimeric copper(II) lipoate is responsible for the extraction:

2Cu2++3(HA)2,o\oversetKex(22)\ightleftharpoons(Cu2A4(HA)2)o+4H+

with the extraction constant, logKex(22)=−11.00. It was proved that lipoate ion coordinates to copper(II) with the carboxylate group without a remarkable participation of the disulfide moiety in the coordination.
Liquid Crystal Materials with Sulfur Atoms Incorporated in the Principal Structure. VI. Optically Active New Smectic Liquid Crystal Compounds with 1,3-Oxathiane or 1,3-Dithiane Ring
Authors: Haramoto Yuichiro , Tomita Yoko , Kamogawa Hiroyoshi
Published: July 2006

(+)-2-Methylbutyl p-(5-alkyl-1,3-oxathian-2-yl)benzoate and -cinnamate (7) were synthesized. The mesomorphic behavior of these compounds were measured. Though (+)-2-methylbutyl p-(5-alkyl-1,3-oxathian-2-yl)benzoate did not exhibit any liquid-crystal phase, the corresponding 1,3-dithiane compounds (8-1, 8-2, and 8-3) and compound (7-4) having R’ of a normal alkyl chain exhibited a smectic phase. This must originate in the wider molecular widths of compounds 7-1, 7-2, and 7-3. Though cinnamate of compounds 7 and 8 exhibited an enantiotropic behavior, the corresponding benzoate did not. This must originate from an increase in the length of the conjugated system and the molecular length.
Visible Light- and Radiation-Induced Alkylation of Pyridine Ring with Alkanoic Acid. Effective Alkylation in the Presence of Iron(III) Sulfate
Authors: Sugimori Akira , Yamada Tetsuo
Published: July 2006

Quinoline and 4-methylquinoline are efficiently alkylated with alkanoic acid in the presence of iron(III) sulfate upon visible light-irradiation. Iron(III) sulfate not only accelerates the photoreaction but also increases the yield of alkylation. Gamma-irradiation also brings about the alkylation. In the photo- and radiation-induced alkylation with alkanoic acid, alkyl radicals play important roles.
A Study on the Mechanism of the Dimerization of Quinazoline Compounds Catalyzed by Cyanide Ions
Authors: Goto Ayako , Higashino Takeo
Published: July 2006

It was shown that an intermediate, 4,4′(3H,3′H)-biquinazolinylidene (2a) was isolated in the formation process of 4,4′-biquinazolinyl (3a) which was obtained from the reaction of quinazoline (1a) with potassium cyanide, and 2a was readily oxidized to 3a by oxygen in air. The dimerization process was studied kinetically by NMR method. The result showed that the process was essentially similar to that of the benzoin condensation. The introduction of a methyl group into the C2-position of 1a resulted in a lowering of the reaction rate because the activation energy of 2-methylquinazoline (1b) dimerization became higher compared with that of 1a dimerization.
An Improved Method for Stereoselective Synthesis of (E)-Alkenes via Alkenyldialkylboranes
Authors: Hoshi Masayuki , Masuda Yuzuru , Arase Akira
Published: July 2006

Successive treatments of alkenyldialkylboranes, formed by the reaction of alkynes and sterically hindered dialkylboranes, with alkyllithium and benzenesulfenyl chloride afforded highly pure (E)-alkenes in good or excellent yields.
Control of Product in the Reaction of Tributyltin ω-Haloalkoxide (n-Bu3SnO(CH2)nX) with Diphenylketene
Authors: Shibata Ikuya , Baba Akio , Matsuda Haruo
Published: July 2006

The reaction of tributyltin ω-haloalkoxide with diphenylketene gave cyclic ketene acetals and/or lactones, and the ratio of these products were controled by the number of methylene groups and by the addition of Lewis base in the reaction system. Moreover, the direct cycloaddition of diphenylketene with cyclic ethers proceeded in high yields, catalyzed by organotin halide–Lewis base complexes.
Synthesis and Biological Activities of d-Homoglutamine Analogs of Substance P
Authors: Hashimoto Tadashi , Uchida Yoshiki , Nishijima Miwako , Moro Tadashi , Sakura Naoki , Hirose Kyoko
Published: July 2006

Six substance P (SP) analogs substituted by d-homoglutamine (Hgn) at position 5 or/and 6 were prepared by the solid phase method. The activity of the peptides was assayed on the smooth muscles of the isolated guinea pig ileum and trachea. Results indicate that the substitution of d-Hgn for Gin residue(s) reduces the activity. [d-Hgn6]-SP (4–11) 5 acted as an antagonist of SP.
Novel Glycosidation of 4-Demethoxyanthracyclinones by the Use of Trimethylsilyl Triflate. Syntheses of Optically Active 4-Demethoxydaunorubicin and 4-Demethoxyadriamycin
Authors: Kimura Yoshikazu , Suzuki Michiyo , Matsumoto Teruyo , Abe Rumiko , Terashima Shiro
Published: July 2006

Optically pure (+)-4-demethoxydaunorubicin has been prepared by a novel glycosidation reaction of (+)-4-demethoxydaunomycinone with (−)-3-N-trifluoroacetyl-1,4-bis(O-p-nitrobenzoyl)-l-daunosamine in the presence of trimethylsilyl triflate, followed by sequential O- and N-deprotection reactions. Total synthesis of optically pure (+)-4-demethoxyadriamycin has been also accomplished by two different synthetic schemes, starting from (+)-4-demethoxydaunorubicin or by way of (+)-3′-N-trifluoroacetyl-4-demethoxyadriamycin. (+)-4-Demethoxyadriamycin prepared by our hands was fully characterized by its spectral properties.
Absolute Configuration and Circular Dichroism Spectrum of all-cis(NO2,N,O)-(−)450CD[Co(NO2)2(gly)2]− Complex
Authors: Fujinami Shuhei , Miyamae Hiroshi , Miura Takahiro , Fushimi Koichi
Published: July 2006

An X-Ray analysis of all-cis(NO2,N,O)-(−)450CDK[Co(NO2)2(gly)2]·1/2H2O has been carried out. The crystal form is trigonal, P3121, with a=10.747(1), c=18.589(4) Å and Z=6. The structure was refined by a block-diagonal least-squares method to a final R value of 0.047 for 3207 independent reflections with |Fo|>3σ(|Fo|). The absolute configuration of the (−)450CD[Co(NO2)2(gly)2]− ion has been determined to be Δ(R). By comparing the CD spectrum of Δ(R)-[Co(NO2)2(gly)2]− with that of a related Λ(R)-[Co(NO2)2(en)(ox)]− complex, the optical activities of these complexes have been concluded to be derived largely from helical distributions of chelate rings.
Synthesis of Sydnone Compounds Substituted by Heteroatom Groups at the 4-Positions
Authors: Fuchigami Toshio , Chen Ching-Sy , Nonaka Tsutomu , Yeh Mou-Yung , Tien Hsien-Ju
Published: July 2006

A general method for the introduction of heteroatoms to the 4-position of a sydnone ring was developed. Various 4-alkylthio- and 4-arylthiosydnones were prepared in excellent yields by the reaction of 3-aryl-4-lithiosydnones (2) with dialkyl and diaryl disulfides. Treatment of 2 with diaryl diselenides, diphenylphosphinous chloride, and arsenic trichloride provided 3-aryl-4-(arylseleno)sydnones, (3-aryl-4-sydnonyl)diphenylphosphine and tris(3-aryl-4-sydnonyl)arsine, respectively, in good yields. It was also found that the reactivity of sydnonyl anions derived from 2 was quite different in some cases from that of the corresponding ordinary aromatic analogues, though the sydnone ring has a somewhat aromatic nature.
Efficient Synthesis of a New Amino Acid, (2S,3R,4R)-4-Chloro-3-hydroxyproline
Authors: Lee Sannamu , Kodera Yasushi , Noda Kosaku , Aoyagi Haruhiko , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

An unusual new amino acid, (2S,3R,4R)-4-chloro-3-hydroxyproline, was stereospecifically synthesized through a four-intermediate from Boc-3,4-dehydro-l-proline. The obtained product was stable in a mild alkaline solution.
Immobilization of β-Cyclodextrin on Silica Gel
Authors: Shiraishi Shinsaku , Komiyama Makoto , Hirai Hidefumi
Published: July 2006

β-Cyclodextrin (β-CyD) was covalently immobilized on silica gel by chlorination of silica gel with thionyl chloride or silicon tetrachloride, followed by the reaction of the resulting chlorinated silica gel with β-CyD in pyridine. The amounts of the immobilized β-CyD were 8×10−5 to 1.4×10−4 mol per 1 g of the β-CyD–silica gel composites. On heating, the composites did not exhibit weight decrease up to 250 °C. The β-CyD in the composites formed 1 : 1 complex with phenol in aqueous solutions, and the equilibrium constant for the dissociation of the complex was 6×10−3 mol dm−3 at 25 °C. The immobilized β-CyD exhibited catalytic activity in the cleavage of 4-nitrophenyl acetate at 25 °C, pH 8.7.
Stereoselective Preparation of Acyclic syn-β-Amino Alcohols from β-Hydroxy Ketones via the Corresponding O-Benzyl Oximes
Authors: Narasaka Koichi , Ukaji Yutaka , Yamazaki Shigeru
Published: July 2006

Reduction of β-hydroxy ketone O-benzyl oximes with lithium aluminum hydride in the presence of sodium or potassium methoxide afforded the corresponding syn-β-amino alcohols in highly stereoselective manner. A lythraceae alkaloid, lasubine II, was synthesized stereoselectively by applying this method.