bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intramolecular Ene Approach to Stereocontrolled Synthesis of Cyclopentanoids
Authors: Takahashi Kazuhiko , Sato Hisao , Mikami Koichi , Nakai Takeshi 
Published: May 2006

Abstract
A new and stereoselective approach to cyclopentanoid synthesis is described. The key step is the thermal intramolecular ene reaction of 4-carbomethoxymethyl-7-benzyloxy-5-heptenal, prepared by the Claisen rearrangement, to afford the 2,3-disubstituted cyclopentanol derivative in a highly stereoselective fashion.
1,2-Asymmetric Induction on Conjugate Addition to Chiral γ-Sukstituted-α,β-unsaturated Aldehyde
Authors: Honda Yutaka , Hirai Shigeru , Tsuchihashi Gen-ichi 
Published: May 2006

Abstract
The conjugate addition of organo-cuprate and -copper reagents to chiral γ-substituted-α,β-unsaturated aldehydes yields the anti-adducts predominantly.
A Convenient Synthesis of Cyclic Ethers from Siloxy Carbonyl Compounds
Authors: Homma Koichi , Mukaiyama Teruaki 
Published: May 2006

Abstract
Five–seven membered cyclic ethers are prepared by one-pot procedure in good yields from γ-, δ-, and ε-siloxy carbonyl compounds, respectively, on treatment with silyl nucleophiles (triethylsilane, allyltrimethylsilane, trimethylsilyl cyanide, etc.) in the presence of a catalytic amount of trityl hexachloroantimonate, or a catalyst system of antimony pentachloride, chlorotrimethylsilane and tin (II) iodide.
Novel Synthetic Method of Phenol from Benzene Catalysed by Perfluorinated Hemin
Authors: Tsuchiya Shinji , Seno Manabu 
Published: May 2006

Abstract
New perfluorinated hemin carrys out hydroxylation of benzene by hydrogen peroxide at room temperature and an atmospheric pressure. The turnover for phenol produced for 2 hours is 55. This hemin also catalyses the epoxidation of cyclooctene by hydrogen peroxide.
Ecklonialactone-A and -B, Two Unusual Metabolites from the Brown Alga Ecklonia stolonifera Okamura
Authors: Kurata Kazuya , Taniguchi Kazuya , Shiraishi Kazunari , Hayama Naoki , Tanaka Isao , Suzuki Minoru 
Published: May 2006

Abstract
Two new unusual metabolites, ecklonialactone-A and -B have been isolated from the title alga, and their structures were determined by spectral and chemical methods as well as X-ray crystallographic analysis.
γ-Cyclodextrin as a Second Sphere Coordinating Ligand for Cobalt Cluster Complexes
Authors: Harada Akira , Shimada Masayuki , Takahashi Shigetoshi 
Published: May 2006

Abstract
One-to-one inclusion compounds of di-, tri-, and tetranuclear cobalt complexes with γ-cyclodextrin were obtained in high yields, while α- and β-cyclodextrin did not form inclusion compounds.
Solvent Effects in 1H-NMR Spectrum of Steroidal π-Allyl Palladium Chloride Complexes
Authors: Horiuchi C Akira , Takayama Toshio , Koike Yoshio , Tanaka Mikio , Satoh J Yasuo 
Published: May 2006

Abstract
The 1H-NMR spectra of the steroidal α-π-allyl palladium complexes in which palladium coordinated at the α-face showed higher field shift of C-19 methyl signal in C6D6 than in the case of CDCl3. The configuration of palladium in π-allyl palladium complexes was confirmed by this phenomenon.
Synthesis of (+)-3,4,8,9,13,14,18,19,23,24,28,29-Dodecaethoxy-1,6,11,16,21,26-hexaazacyclotriacontane. The First D6-Symmetry Organic Molecule with Known Absolute Configuration
Authors: Naemura Koichiro , Kanda Yuji , Yamanaka Masatoshi , Chikamatsu Hiroaki 
Published: May 2006

Abstract
The high-symmetry chiral macrocyclic polyamides and polyamines were synthesized by using (+)-tartaric acid as a chiral source. The title compound, one of the amines, is the first D6-symmetry organic molecule with known absolute configuration.
Asymmetric Aldol Reaction of Silyl Enol Ethers with Aldehydes Promoted by the Combined Use of Chiral Diamine Coordinated Tin(II) Triflate and Tributyltin Fluoride
Authors: Kobayashi Shu , Mukaiyama Teruaki 
Published: May 2006

Abstract
Asymmetric aldol reaction of silyl enol ethers of thioesters with aldehydes is performed, in high enantiomeric exess by the use of a new chiral promoter, a combined use of chiral diamine coordinated tin(II) triflate and tributyltin fluoride.
Synthesis and Crystal Structure of Head-to-Head Bis(μ-2-pyridonato-N,O)bis[(ethylenediamine)palladium] Nitrate, [Pd2(en)2(C5H4NO)2](NO3)2
Authors: Suzuki Katsuhiko , Matsumoto Kazuko 
Published: May 2006

Abstract
A synthetic method for preparing exclusively the head-to-head isomer of a dimeric compound [Pd2(en)2(C5H4NO)2](NO3)2 has been reported. Single-crystal X-ray analysis of the compound confirmed the head-to-head structure. The complex is the first example of a head-to-head isomer for a doubly amidate-bridged Pd(II) dimer.
Carbenoid Type Reactions of a Stabilized Bismuthonium Ylide in the Presence of Copper Catalyst
Authors: Ogawa Takuji , Murafuji Toshihiro , Iwata Kazuhiko , Suzuki Hitomi 
Published: May 2006

Abstract
Triphenylbismuthonio-4,4-dimethyl-2,6-dioxocyclohexan-1-ide reacts with 1-alkynes in the presence of small amounts of copper(I) chloride to form bicyclic furan derivatives probably via a carbenoid intermediate.
Preparation, Chiroptical Properties, and Chiral Recognition Ability of Carbamoylated Polyamides Having (−)-Anti Head-to-Head Coumarin Dimer Component
Authors: Saigo Kazuhiko , Nakamura Masataka , Adegawa Yutaka , Noguchi Shinya , Hasegawa Masaki 
Published: May 2006

Abstract
Optically active polyamides having (−)-anti head-to-head coumarin dimer component were easily carbamoylated by polymer reaction with isocyanates. The carbamoylated polyamides formed ordered conformations in the film state and showed high chiral recognition ability for racemates.
Spectroscopic Investigation of Methyl Viologen Radical Cation Included in β-Cyclodextrin
Authors: Ata Masafumi , Aoyagi Makoto , Kubozono Yoshihiro , Gondo Yasuhiko 
Published: May 2006

Abstract
A stable β-cyclodextrin inclusion complex with methyl viologen radical cation has been prepared in solution and in the form of polycrystalline powder, enabling us to study the ESR, electronic absorption, and induced circular dichroism spectra.
Divalent Cation Dependent Spectral Change in Merocyanine Monolayer
Authors: Yoneyama Mitsuru , Nagao Takumi , Murayama Tetsuo 
Published: May 2006

Abstract
The effect of divalent cation on chromophore aggregation in a merocyanine monolayer was studied by means of spectroscopic measurements. The absorption spectra for J-aggregates were found to be controlled by the nature of metal cation.
Preparations of Copper(I) Complexes Ligated with Novel Hindered Pyrazolylborates
Authors: Kitajima Nobumasa , Fujisawa Kiyoshi , Fujimoto Chisato , Moro-oka Yoshihiko 
Published: May 2006

Abstract
Novel hindered pyrazolylborates, HB(3,5-Ph2Pz)3− and HB(3,5-iPr2pz)3− were synthesized. Several copper(I) complexes ligated with these ligands were prepared and their properties are compared with the corresponding complexes with conventional pyrazolylborate as ligand.
Regiospecifically Bifunctional Cyclodextrins Having Two Amino Groups on Secondary Hydroxyl Side
Authors: Fujita Kahee , Egashira Yoshimitsu , Imoto Taiji , Fujioka Toshihiro , Mihashi Kunihide , Tahara Tsutomu , Koga Toshitaka 
Published: May 2006

Abstract
3A, 3X-diamino-3A, 3X-dideoxy-(2AS), (2XS), (3AR), (3XR)-α-cyclodextrins (X = B, X = C, and X = D) were prepared from the reactions of 2A, 3A; 2X 3X-dianhydro-(2AS), (2XS),α-cyclodextrins with aqueous ammonia.
Separation of Oxygen and Nitrogen Due to the Controlled Pore-opening Size of CVD Zeolite A
Authors: Niwa Miki , Yamazaki Kiyoshi , Murakami Yuichi 
Published: May 2006

Abstract
We modified zeolite A by the CVD (chemical vapor deposition) method using silicon methoxide; the CVD zeolite A adsorbs oxygen in preference to nitrogen because of the controlled pore-opening size. This behavior for the adsorption of oxygen and nitrogen is inverse to that usually observed on zeolite A.
Oxidation-Reduction Hydration of Olefins with Molecular Oxygen and 2-Propanol Catalyzed by Bis(acetylacetonato)cobalt(II)
Authors: Mukaiyama Teruaki , Isayama Shigeru , Inoki Satoshi , Kato Koji , Yamada Tohru , Takai Toshihiro 
Published: May 2006

Abstract
In the presence of a catalytic amount of bis(acetylacetonato)cobalt(II), various olefins are hydrated with oxygen and secondary alcohol to afford the corresponding alcohols together with alkanes and ketones via Oxidation-Reduction process. Effect of additives in the present hydration reaction shows that 2,6-lutidine and 2-picoline inhibit the production of alkanes in a large extent to result in the better yielding of alcohols.
A(1,3) strain-Controlled Cyclic Hydroboration of 1,4- and 1,5-Dienes
Authors: Yokoyama Yasushi , Kawashima Hideyuki , Masaki Hideo 
Published: May 2006

Abstract
Cyclic hydroboration of 4-cyclohexylidene-3-methyl-1-butene by thexylborane gave 1-cyclohexyl-2-methyl-1,4-butanediol in 96/4 anti/syn ratio in 72% yield. Similarly, 5-cyclohexylidene-4-methyl-1-pentene gave 1-cyclohexyl-2-methyl-1,5-pentanediol in 95/5 anti/syn selectivity in 47% yield by BH3. This reaction was applied to the stereoselective preparation of a cyclopentanone.
Correlation between the Configurational Structure and the Asymmetric Hydrogenation of Δ1-, Δ2-, and Δ3 -Dehydrotripeptides
Authors: Shin Chung-gi , Ogawa Kazumichi , Morooka Katsuhiro , Yonezawa Yasuchika 
Published: May 2006

Abstract
The heterogeneous catalytic hydrogenation of Δ1 -dehydrotripeptides (Δ1 -DHP), which have a β-turn structure, was carried out to give the corresponding tripeptides indicative of the very large diastereomeric excess, comparing with those from Δ2- and Δ3 -DHPs. The efficient differences of the chiral inductions were found to be closely correlated to the configuration of the respective DHPs.
An Efficient Method for the Hofmann Degradation of Amides by Use of Benzyltrimethylammonium Tribromide
Authors: Kajigaeshi Shoji , Asano Kohichi , Fujisaki Shizuo , Kakinami Takaaki , Okamoto Tsuyoshi 
Published: May 2006

Abstract
The reaction of amides with a calculated amount of benzyltrimethylammonium tribromide in aqueous sodium hydroxide under mild conditions gave corresponding amines in fairly good yields.
Novel Synthesis of (S)-(−)-Chroman-2-carboxylic Acid, Vitamin E Precursor
Authors: Yoda Hidemi , Takabe Kunihiko 
Published: May 2006

Abstract
A new strategy to the synthesis of (S)-(−)-chroman-2-carboxylic acid, a pivotal intermediate possessing the absolute configuration required for the construction of α-tocopherol, was disclosed by utilizing asymmetric halolactonization of acylproline. Debromination followed by acidic hydrolysis directly afforded the title compound in 98% enantiomeric excess.
Reactivity of cis-Bis(dimethylphenylsilyl)bis(phosphine)platinum Complexes toward Unsaturated Compounds Relevant to Double Silylation
Authors: Kobayashi Toshi-aki , Hayashi Teruyuki , Yamashita Hiroshi , Tanaka Masato 
Published: May 2006

Abstract
The reaction of phenylacetylene, tolane, or isoprene with cis-bis(dimethylphenylsilyl)bis(methyldiphenylphosphine)platinum readily took place to result in 1,2- or 1,4- double silylation, respectively. Ethylene also underwent double silylation with the platinum complex, but styrene selectively gave E-2-(dimethylphenylsilyl)styrene.
Novel Halogen Exchange Reactions between Halosilanes and Rh(I) or Ir(I) Complexes
Authors: Yamashita Hiroshi , Kobayashi Toshi-aki , Hayashi Teruyuki , Tanaka Masato 
Published: May 2006

Abstract
Vaska-type complexes such as MCl(CO)L2 (M = Rh or Ir, L = tertiary phosphine) or the Wilkinson complex RhCl(PPh3)3 underwent halogen exchange reactions with halosilanes Me3SiX (X = Br, I) to give MX(CO)L2 or RhX(PPh3)3 respectively with the formation of Me3SiCl. The reaction of RhH(CO)(PPh3)3 with MeSiCl3 also afforded RhCl(CO)(PPh3)2.
Photoreaction of 2-Aryl-4-methylpent-2-enenitrile Giving 1-Aryl-1-cyano-2,2-dimethylcyclopropane. The Substituent Effect of 1,2-Hydrogen Migration
Authors: Kumagai Tsutomu , Segawa Toru , Miyashi Tsutomu , Mukai Toshio 
Published: May 2006

Abstract
The photorearrangement of 2-aryl-4-methylpent-2-enenitriles to arylcyclopropanes is discussed on the basis of substituent effect. The efficiency of 1,2-hydrogen migration is independent from an electronic effect of the substituent and correlated to the singlet energy of excited molecule.
Removal of Cyclic Di-t-butylsilanedlyl Protecting Groups Using Tributylamine Hydrofluoride (TBAHF) Reagent
Authors: Furusawa Kiyotaka 
Published: May 2006

Abstract
Cyclic di-t-butylsilanediyl protecting groups were rapidly and cleanly removed from 3′,5′-cyclic silanediyl nucleosides by a mild and convenient reagent, tributylamine hydrofluoride in tetrahydrofuran.
Bis(trifluoroacetylacetonato)cobalt(II) Catalyzed Oxidation-Reduction Hydration of Olefins Selective Formation of Alcohols from Olefins
Authors: Inoki Satoshi , Kato Koji , Takai Toshihiro , Isayama Shigeru , Yamada Tohru , Mukaiyama Teruaki 
Published: May 2006

Abstract
Various olefins are hydrated with molecular oxygen (oxidant) and a secondary alcohol (reductant) in the presence of a catalytic amount of bis(trifluoroacetylacetonato)cobalt(II) in good yields.
Preparation and Characterization of BiTaS3 a New Layered Ternary Sulfide
Authors: Oosawa Yoshinao , Gotoh Yoshito , Onoda Mitsuko 
Published: May 2006

Abstract
BiTaS3, a new layered ternary sulfide, has been prepared from the elements. The X-ray diffraction pattern of the sulfide is indexed on the basis of pseudo-orthorhombic cell with the lattice parameters of a = 6.10 Å, b = 38.3 Å, and c = 23.115 Å.
How Active p-Quinone Dianions Are as Proton Acceptors!
Authors: Uno Bunji , Kawabata Atsushi , Kano Kenji 
Published: May 2006

Abstract
Formation constants of two-point hydrogen-bonded complexes of p-quinone dianions with CH3OH (1:2) have been successfully determined to be of the order of 104 dm6 mol−2. The origin of high reactivity of the dianions toward proton donors has been clarified experimentally and theoretically.
Template Synthesis and Structure of a Dilead(II) Complex of a Macrocycle with N8O2 Donor Set
Authors: Sakiyama Hiroshi , Tokuyama Ken-ichi , Nishio Jun , Matsumoto Naohide , Okawa Hisashi 
Published: May 2006

Abstract
A new tetranucleating macrocycle (H2L) comprised of 2,6-diformyl-4-methylphenol and 1,8-diamino-3,6-dimethyl-3,6-diazaoctane in the 2:2 ratio was obtained as a lead(II) complex of the formula Pb2(H2L)(dmf)4(ClO4)4, whose crystal structure was determined by X-ray method.
Selective Reduction of NO with Propane on Gallium Ion-exchanged Zeolites
Authors: Yogo Katsunori , Tanaka Satoru , Ihara Michito , Hishiki Tatsuya , Kikuchi Eiichi 
Published: May 2006

Abstract
The reduction of NO with propane in the presence of excess oxygen was investigated using gallium ion-exchanged zeolite catalysts, among which ferrierite(Ga-ferrierite) and ZSM-5(Ga-ZSM-5) showed high activity in a wide range of reaction temperature.
Bi-functional Oxygen Electrode Using Large Surface Area Perovskite-type Oxide Catalyst for Rechargeable Metal-Air Batteries
Authors: Shimizu Youichi , Matsuda Haruyuki , Miura Norio , Yamazoe Noboru 
Published: May 2006

Abstract
Gas-diffusion electrodes loaded with large surface area perovskite-type oxides, La0.6Ca0.4Co0.8B′0.2O3 (B′ = Mn, Fe, Co, Ni, Cu), were examined for the electro-chemical reduction and evolution of oxygen in 7 M KOH at 25 °C. The oxide with B′ = Fe gave the highest bi-functional performances, i.e., 200 mA/cm2 for the oxygen reduction in air and 300 mA/cm2 for the oxygen evolution at −150 and +620 mV vs. Hg/HgO, respectively, owing to its high catalytic activity for the decomposion of the HO2− intermediate.
Synthesis of (+)-Boronolide from d-Glucose
Authors: Nagano Hajime , Yasui Hiroe 
Published: May 2006

Abstract
(+)-Boronolide (= (1′R,2′R,3′S,6R)-5,6-dihydro-6-[1′,2′,3′-tris(acetoxy)heptyl]-2H-pyran-2-one) (1), a constituent isolated from Tetradenia fruticosa and T. barberae (Lamiaceae), was synthesized in 7 steps and in 5.2% overall yield from 2,3,4,5,6-penta-O-benzyl-d-glucose, whose four asymmetric centers were incorporated in 1.
Intermediates for Photoisomerization of a Butenylnaphthalene in the Presence of Electron Acceptors as Studied by Solvent Dependence of Magnetic Field Effects
Authors: Naitoh Kazuhiko , Oguchi Takahisa , Nakagaki Ryoichi , Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi , Nagakura Saburo 
Published: May 2006

Abstract
The external magnetic field effect as well as laser flash photolysis was employed to estimate the contribution of ion radical pairs to isomerization of trans-2-(3,3-dimethyl-1-butenyl)naphthalene (t-BN) in the presence of an electron acceptor in various solvents. The precursor of isomerization, t-BN triplet, was produced most efficiently almost through an exciplex in chloroform (ε = 4.8) among the employed solvents.
Synthesis, Structure, and Magnetic Properties of a Novel Copper(II) Analogue of the Hemerythrin Active Center
Authors: Tokii Tadashi , Nagamatsu Megumi , Hamada Hironobu , Nakashima Michio 
Published: May 2006

Abstract
A novel binuclear copper(II) complex with a μ-hydroxo-bis(μ-carboxylato)dicopper core has been prepared. The crystal structure of the complex consists of dimeric [Cu2(OH)(HCOO)2(bpy)2]+ cations. The magnetic susceptibility data of the complex revealed that a ferromagnetic spin interaction exists in this complex.
A Novel Method for Preparation of Glycerol Monoesters from Glycidyl Esters with Molecular Oxygen Catalyzed by Ni(II) Complex
Authors: Mukaiyama Teruaki , Imagawa Kiyomi , Yamada Tohru , Takai Toshihiro 
Published: May 2006

Abstract
In the presence of a catalytic amount of bis(3-methyl-2,4-pentanedionato)nickel(II) (Ni(mac)2), various glycidyl esters are converted into the corresponding glycerol monoester derivatives with molecular oxygen in good to high yields.
Simultaneous Measurements of Absorbance and Volume Changes of a Photoresponsive Polyacrylamide Microgel in Water
Authors: Ishikawa Masazumi , Misawa Hiroaki , Kitamura Noboru , Irie Masahiro , Masuhara Hiroshi 
Published: May 2006

Abstract
The dynamics of photostimulated volume expansion of a polyacrylamide microgel containing triphenylmethane leucocyanide (TPMCN) in water was studied by simultaneous measurements of the time response of absorbance of triphenylmethyl cation (Abs(t)) and the radius of the gel (R(t)). The time response of the degree of ionic dissociation of TPMCN (α(t)) in the gel was obtained by analyzing Abs(t) and R(t) for the first time. The change in R(t) was shown to be slower than that in α(t).
The Reaction of Disilylacetylenes with Cyclopentadienyl Manganese. Formation of Vinylidene Complexes by 1,2-Silyl Shift
Authors: Sakurai Hideki , Fujii Takeaki , Sakamoto Kenkichi 
Published: May 2006

Abstract
Both cyclic and acyclic acetylenes substituted by two silyl groups on each end undergo facile 1,2-silyl shift in the reaction with cyclopentadienyltricarbonylmanganese under photochemical conditions to give 2,2-disilylvinylidene complexes. Several interesting reactions of the novel complexes are described.
Circularly Polarized Luminescence of [Ru(diimine)3]2+-Ag+ Exciplex System
Authors: Tsubomura Taro , Igarashi Osamu , Morita Makoto 
Published: May 2006

Abstract
Circularly polarized luminescence of [Ru(diimine)3]2+-Ag+ exciplexes in aqueous solution (diimine = 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen)) was studied. Remarkable enhancement of the emission dissymmetry factor gem is observed for the exciplex.
Enzymatic Oxidation Polymerization of o-Phenylenediamine
Authors: Kobayashi Shiro , Kaneko Isao , Uyama Hiroshi 
Published: May 2006

Abstract
Enzymatic oxidation polymerization of o-phenylenediamine using horseradish peroxidase as a catalyst was carried out in an aqueous organic solvent. Polymeric materials with average molecular weight of 20 000 were obtained. The structure of the polymer was found to be composed mainly from imino-2-aminophenylene unit from 13C NMR analysis.
Control of Ring-Junction Stereochemistry via Radical Cyclization. A New Construction of trans-Decalins
Authors: Kawaguchi Mami , Satoh Shoji , Mori Miwako , Shibasaki Masakatsu 
Published: May 2006

Abstract
A stereoselective synthesis of trans-decalins has been developed by use of regiocontrolled 6-endo-trig-radical cyclization of alkenyl bromides with an exo-methylene group in cyclohexane ring.
Preparation and Structure of Phosphono Sugar N-Glycosides
Authors: Yamashita Mitsuji , Iida Akihito , Ikai Koichi , Oshikawa Tatsuo , Hanaya Tadashi , Yamamoto Hiroshi 
Published: May 2006

Abstract
Treatment of 1-phenyl-2-phospholene 1-oxide with N-bromoacetamide or bromine afforded threo and erythro bromohydrins, the latter being converted into novel N-glycosides by reaction with amines. The N-t-butyl phosphono sugar glycoside exists in the 2E conformation.
4,7-Bis(1,3-dithiol-2-ylidene)-4,7-dihydro-2,1,3-benzothiadiazoles. A Novel Type of Electron Donors Affording Organic Metals
Authors: Yamashita Yoshiro , Tanaka Shoji , Imaeda Kenichi , Inokuchi Hiroo , Sano Mizuka 
Published: May 2006

Abstract
The title compounds, tetrathiafulvalene (TTF) analogues with a quinoid structure fused with a 1,2,5-thiadiazole ring, are strong electron donors, and the tetramethyl derivative gave highly conductive cation radical salts showing metallic temperature dependence down to 100 K.
Increment of Photocatalytic Killing of Cancer Cells Using TiO2 with the Aid of Superoxide Dismutase
Authors: Cai Ruxiong , Hashimoto Kazuhito , Kubota Yoshinobu , Fujishima Akira 
Published: May 2006

Abstract
It was found that the efficiency of photocatalytic killing of cancer cells with TiO2 particles under aerial condition was increased by adding superoxide dismutase (SOD). This enhancement effect of SOD was suppressed when catalase, hydrogen peroxide scavenger, was added to the system. These results can be reasonably explained by the efficient conversion of photogenerated superoxide anion into hydrogen peroxide with the aid of SOD.
Discokiolides. Cytotoxic Cyclic Depsipeptides from the Marine Sponge Discodermia kiiensis
Authors: Tada Haruhiko , Tozyo Takehiko , Terui Yoshihiro , Hayashi Fumiaki 
Published: May 2006

Abstract
Cytotoxic cyclic depsipeptides discokiolides A-D were isolated from the marine sponge Discodermia kiiensis as methyl esters. The structures were mainly determined by NMR techniques. Discokiolides are the unique depsipeptides containing oxazole ring.
Highly Selective Copper(II) Extraction with Oligoethylene Glycol Bis(hydrazone)s as Several Compositional Complexes
Authors: Sakamoto Hidefumi , Ishikawa Junichi , Nakagami Hiroyuki , Ito Yasuaki , Ogawa Kazuyoshi , Doi Kunio , Otomo Makoto 
Published: May 2006

Abstract
High Cu2+ ion selectivity in the solvent extraction was spectrophotometrically exhibited by using the non-cyclic polyether derivatives bearing a 5-nitro-2-pyridylhydrazone at each end of the bridging chain. The species of Cu2+ complexes extracted were changed with the variation of additional alkali metal salts.
Gas Phase Basicities of Acetophenones toward Trimethylsilyl Cation
Authors: Mishima Masaaki , Kang Chul Hyun , Fujio Mizue , Tsuno Yuho 
Published: May 2006

Abstract
The substituent effect on gas phase basicities toward Me3Si+ has been studied for acetophenone bases. It is shown that the magnitude of the ρ value is the same as the corresponding value for the proton basicities while contribution of resonance effect of para π-donors is reduced somewhat in Me3Si+ basicities.
Discrimination of Steroid Hormones by Novel Cage-type Azacyclophanes Bearing Chiral Binding Sites
Authors: Murakami Yukito , Hayashida Osamu , Ito Tosihiro , Hisaeda Yoshio 
Published: May 2006

Abstract
Novel cage-type azacyclophanes bearing chiral binding sites provided by l- and d-valine residues exhibited discrimination toward steroid hormones in D2O–CD3OD (3:1 v/v), as effected by hydrophobic and π–π interactions. In addition, chirality-based discrimination of α- and β-estradiol was attributed to their different modes of hydrogen bonding with the hosts.