bluuebunny/crossref_metadata_2025 huggingface dataset:
Cycloaddition Reactions of N-Sulfinylsulfonamides with Ketenimines
Authors: Minami Toru , Takimoto Futoshi , Agawa Toshio
Published: July 2006

N-Sulfinylsulfonamides, 1a, b, reacted with ketenimines, 2, in ether to give the unstable [2+2] cycloadducts, 3-ylidene-1,2,4-thiadiazetidin-1-oxides, 3, which were then readily hydrolyzed to the N,N′’-disubstituted amidine derivative, 4, in good yields. The reaction of N-sulfinylmethanesulfonamide (1b) with diphenylketen-N-p-tolylimine (2d) at 130 °C gave the exchange product, N-sulfinyl-p-toluidine (5) in a 70% yield via the intermediate cycloadduct. In contrast to 2d, the reaction of N-sulfinyl-p-toluenesulfonamide (1a) and phenylethylketen-N-phenylimine (2f), under the same conditions, led to the formation of a mixture of N-phenyl-N′-p-toluenesulfonyl-2-phenyl-trans- (6a) and cis-2-butenoamidine (6b) in an 81% yield.
Dielectric Dispersion and Relaxation Mechanism in Some Trifluoro Compounds at Microwave Frequencies
Authors: Purohit H D , Sharma H S , Vyas A D
Published: July 2006

The permittivity and dielectric loss of 2,2,2-trifluoroethanol and trifluoroacetic acid have been measured in benzene solutions at three microwave frequencies, 24.01, 9.83, and 6.01 GHz and also at 1 MHz and optical frequency at 35 °C. The permittivity and dielectric loss at different frequencies have been plotted against concentration (wt. fraction). The slopes of these straight lines have been used for the complex plane plots (a′ vs.  a″). The complex plane plots for 2,2,2-trifluoroethanol and trifluoroacetic acid are of the Cole-Cole type. The relaxation time (τ0) and distribution parameter (α) have been calculated. The values of dipole moments (μ) of these compounds have also been calculated and reported, The relaxation mechanism in these two compounds has been explained.
Chemistry of Nitrosoimines. XII. Reactions of 3-Substituted 2-Nitrosoimino-2,3-dihydrobenzothiazoles with Alkyl Grignard Reagents
Authors: Akiba Kin-ya , Hisaoka Motoyuki , Kawamura Takayuki , Inamoto Naoki
Published: July 2006

3-Substituted 2-nitrosoimino-2,3-dihydrobenzothiazole (1) reacts with primary or secondary alkyl Grignard reagents to afford bis[o-(N-substituted amino)phenyl] disulfide, 3-substituted 2-N′-alkyl- and 2-N′,N′-dialkylhydrazono-2,3-dihydrobenzothiazoles as major products. In the reactions with secondary alkyl Grignard reagents, 3-substituted 2-N′-alkylidenehydrazono-2,3-dihydrobenzothiazole was also produced. The general feature of the reaction of 1 with Grignard reagents has been summarized and is discussed.
Syntheses of Tetracyclo[7.3.0.03,7.04,10]dodecane-2,8-dione (“[8]Diisotwistane-2,8-dione”) and8,9-Benzotricyclo[4.3.1.03,7]decane (“Benzoisotwistane”)
Authors: Nakazaki Masao , Naemura Koichiro , Yoshihara Hiroyuki
Published: July 2006

Tetracyclo[7.3.0.03,7.04,10]dodecane-2,8-dione (“[8]diisotwistane-2,8-dione”) was synthesized from trans-anti-2,5-dioxo-7,8-diethoxycarbonylbicyclo[2.2.2]octane which was prepared by the Diels-Alder reaction of hydroquinone with diethyl fumarate. 8,9-Benzotricyclo[4.3.1.03,7]decane (“benzoisotwistane”) was also synthesized from 2-oxo-5-endo-ethoxycarbonyl-7,8-benzotricyclo[2.2.2]octane which was obtained by the Diels-Alder reaction of β-naphthol with ethyl acrylate.
Peptides Containing Aminophosphonic Acids. III. The Synthesis of Tripeptide Analogs Containing Aminomethylphosphonic Acid
Authors: Yamauchi Kiyoshi , Mitsuda Yasuhiro , Kinoshita Masayoshi
Published: July 2006

A synthetic method for tripeptide analogs containing aminomethylphosphonic acid has been described.
Kinetics and Mechanism of Oxidation of d(+)-Sorbose by Chloramine-T
Authors: Sanehi R , Gupta K C , Mehrotra R M , Mushran S P
Published: July 2006

The kinetics of oxidation of d(+)-sorbose by chloramine-T has been investigated in high alkaline media. The reaction shows a brief induction period after which a first order dependence in both chloramine-T and substrate is followed. The order in hydroxide ion is observed as fractional being 1.3 under the experimental conditions. The values of energy of activation, frequency factor and entropy of activation have been computed as 28.2 kcal mol−1, 2.90×1019 1 mol−1 s−1 and +29.8 e.u. respectively. A plausible mechanism consistent to the experimental result is proposed.
Racemization of Amino Acid Residues Fused in Thiazoline, Oxazoline, and Imidazoline Rings
Authors: Yonetani Ken , Hirotsu Yoshihiro , Shiba Tetsuo
Published: July 2006

For the purpose of study on racemization of exo methine carbon atom of thiazoline, oxazoline or imidazoline ring, the following four compounds were synthesized from amino acid imino ether: 2-(1-benzyloxycarbonylaminoethyl)-2-thiazoline (I), methyl 2-(1-benzyloxycarbonylaminoethyl)-2-thiazoline-4-carboxylate (II), methyl 2-(1-benzyloxycarbonylaminoethyl)-2-oxazoline-4-carboxylate (III), and 2-(1-benzyloxycarbonylaminoethyl)-2-imidazoline (IV). A racemization rate of the alanine residue was measured from an optical rotation of 2,4-dinitrophenyl derivative obtained from the acid hydrolyzate and from hydrogen-deuterium exchange reaction at α-carbon atom. All these compounds were found to be racemized very easily particularly in the presence of proton source. From the experimental results, a plausible mechanism for racemization peculiar to such heterocyclic compounds through protonation-deprotonation process was presented.
Photochemical Reactions of Azido-1,3,5-triazines with Hydrocarbons and Ketones
Authors: Kayama Ryuichi , Shizuka Haruo , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

2-Azido-4,6-dimethoxy-1,3,5-triazine (1) produced 2-cyclohexylamino-4,6-dimethoxy-1,3,5-triazine as the sole major product upon irradiation at 254 nm in cyclohexane by the intermolecular insertion of the triazinyl nitrene into cyclohexane, while in the reaction with cyclohexene a derivative of the aziridine type was produced by the addition of triazinyl nitrene to the double bond of cyclohexene. In the photochemical reaction of 1 with ketones, 3,3-dialkyl derivatives of 5,7-dimethoxy-3H-[1,2,4]oxadiazolo[4.3-a]-s-triazine were obtained. The reaction is assumed to proceed via the electrophilic attack of the singlet nitrene on the carbonyl oxygen of the ketones followed by cyclization to give the final products. However, in the thermal reaction of 1 with ketones only 2-amino-4,6-dimethoxy-1,3,5-triazine was obtained.
The Substituent Effect. X. Solvolysis of 3- and 4-Substituted 1-(1-Naphthylethyl) Chlorides
Authors: Tsuno Yuho , Sawada Masami , Fujii Takahiro , Yukawa Yasuhide
Published: July 2006

The rates of the solvolysis of eleven 3- and 4-substituted 1-(1-naphthylethyl) chlorides were determined in 80% (v/v) aqueous acetone solution at 45 °C. The effect of substituents in 3- and 4-positions of the naphthalene can be correlated with the LArSR relationship (logk⁄k0)3α,4α=−5.12(σ0+1.04Δ\barσR+)−0.12 (correlation coefficient, 0.999; standard deviation, ±0.12). The ρ value in the naphthalene is slightly larger and the r value is slightly smaller than values in the corresponding benzene system under the same condition (ρ=−4.95, r=1.15). The difference is reasonably interpreted in terms of the steric effect for the peri-hydrogen relative to the reaction center at the α-position of the naphthalene. The effect of substituents can be correlated with the LSFE relationship for conjugatively electron releasing groups with high precision (R>0.999) in the series, 3α and 4α; (logk⁄k0=ρiσi+ρπ+σπ+). In this solvolysis, the 3α/4α inductive ratio, ρi,3α/ρi,4α was 1.37, only slightly larger than the meta/para inductive ratio of 1.17 for the corresponding reaction in the benzene series. The applicability of these equations to 3- and 4-substituted α-naphthyl system is also shown for some other reactivities.
The Chlorine Nuclear Quadrupole Resonance in an Organic Free Radical, p-Cl-EDPA
Authors: Yoshioka Toshio , Yamauchi Jun , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo
Published: July 2006

The 35Cl nuclear quadrupole resonance in a stable organic free radical, 1,3-bisdiphenylene-2-p-chlorophenyl-allyl, has been measured from 4.2 to 1.6 K. On lowering the temperature, the resonance line became weaker and broader, and it disappeared near the Néel temperature. This behavior has been interpreted in terms of the presence of a hyperfine interaction.
The Substituent Effect. XI. Solvolysis of 5-, 6-, and 7-Substituted 1-(1-Naphthylethyl) Chlorides
Authors: Tsuno Yuho , Sawada Masami , Fujii Takahiro , Tairaka Yoshihiko , Yukawa Yasuhide
Published: July 2006

Fourteen 5-, 6-, and 7-substituted 1-(1-naphthylethyl) chlorides were prepared and the solvolysis rates were determined in 80% (v/v) aqueous acetone at 45 °C. The effects of −R substituents at respective positions were treated on the basis of the equation, logk⁄k0=ρiσi+ρx+σx+=ρ(Cijσi+qrij+σπ+). The position dependency of the inductive effect was given by Cij(=ρi⁄ρi,4α); C3α=1.37, C4α=1.00, C5α=0.75, C6α=0.57, and C7α=0.72. The Cij values appear to be correlated with Dewar’s simplified field function 1/rij. The position dependency of Pi-electronic effect given by the ratio ρπ+⁄ρi,4α=qr·ij+ was consistent with the prediction from the MO indices, such as Forsyth’s Δqij(ArCH2+ parameters. The same treatment was applied also to three other naphthalene reactivities, detritiation, pKa of α-naphthoic acids and pKa of naphthylammonium ions. The linear ρi–ρi relation holds among these reactions, suggesting a reaction-independent scheme of the inductive transmission. The qr·ij+ values vary at conjugate positions with reaction but not at non-conjugate positions irrespective of reactions. The results are discussed in comparison with those of relevant treatments.
The Effects of the Properties of Trunk Polymers on the Flocculating Action of Graft Copolymers
Authors: Miyata Namiko , Sakata Isao , Senju Ryoichi
Published: July 2006

Acryl amide (AM) was graft copolymerized onto hydroxy ethyl cellulose (HEG), poly vinyl alcohol (PVA), amylose (AL), and amylopectin (AP), whose molecular extensions in an aqueous solution are different. The graft copolymers were then purified by means of fractional precipitation. The effects of the properties of the trunk polymers of the graft copolymers on their jlocculating action for kaolin suspensions were examined. It was found that: 1) when the molecular weights (\barMn) of the copolymers were equal, their flocculating action was much influenced by the kind of trunk polymer (HEC, AL, PVA, and AP) and decreased in that order; 2) the differences in their flocculating action are due to the differences in their molecular extensions in an aqueous solution; and 3) the flocculating action of the copolymers increased with an increase in the \barMw of the branched poly AM (PAM), but was, however, scarcely affected by a small number of grafted PAM per trunk polymer molecule.
ESR Studies of the Triplet-state Dimers of Michler’s Ketone Metal Ketyls in Glassy Solutions
Authors: Fujita Hideo , Kako Saburo , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo
Published: July 2006

The ESR spectra (the ΔMs=±1 and ΔMs=±2 transitions) of the triplet-states of Michler’s ketone metal ketyl dimers are observed in glassy solutions at 77 K. For these metal ketyl dimers, the correlation of the mean separation between spins to the radius of the counter cation was experimentally examined.
Structural Changes of Iron Oxides by Ball-Milling in Different Media
Authors: Uehara Yasuhiko
Published: July 2006

γ-Fe2O3, Fe3O4, and α-Fe2O3 subjected to steel ball-milling in water changed into a spinel-type solid solution, while in polar organic media no remarkable changes occurred. In non-polar media, the γ-Fe2O3 and a part of the Fe3O4 were transformed into α-Fe2O3, although α-Fe2O3remained unchanged. The diffraction lines of the resulting α-Fe2O3 broadened markedly.
Weak Fluorescence from [2.2]Metacyclophane
Authors: Shizuka Haruo , Ogiwara Toshio , Morita Toshifumi
Published: July 2006

Weak fluorescences from [2.2]metacyclophane (MCP) were observed: the normal and intramolecular excimer fluorescences were at 305 and 361 nm respectively. It has been shown that a rapid radiationless deactivation due to the interaction between the two benzene rings in MGP occurs preferentially and the excimer formation responsible for the photocyclization takes place to a small extent.
Mechanism of the Acceleration Effect of 1,10-Phenanthroline on the Rate of Color Change of Xylenol Orange in the Chelatometric Titration of Nickel(II)
Authors: Murayama Teisuke , Takemura Michio
Published: July 2006

The effect in the title was studied kinetically. Experimental results indicate that the color change reaction in the presence of 1,10-phenanthroline proceeds according to a mechanism proposed by Nakagawa and Wada.
Solubility of Transition Metal Complexes in Aqueous Salt Solutions. II. Tris(1,10-phenanthroline)iron(II)Perchlorate in Hydrophobic Salt Solutions
Authors: Miyoshi Katsuhiko , Shimada Chiyori , Yoneda Hayami
Published: July 2006

Solubility of tris(1,10-phenanthroline)-iron(II) perchlorate in water was found to be much increased by the addition of hydrophobic ions. This was interpreted in terms of hydrophobic interaction of the complex cation with hydrophobic ions added.
Mechanism of the Formation of Phenyltolylmethane by the Reaction of Toluene with Phosphorus Trichloride and Oxygen
Authors: Okamoto Yoshiki , Sakurai Hiroshi
Published: July 2006

The formation of phenyltolylmethane by the reaction of toluene with PCl3 and oxygen was shown to proceed by electrophilic attack on toluene by the benzyl cation, resulting from the decomposition of the trichlorobenzyloxyphosphoranyl peroxy radical (PhCH2OPCl3OO·).
Studies on Nitro Sugars. VI. Synthesis of Methyl 2-Deoxy-2-nitro-α-d-glucopyranoside Derivatives
Authors: Takamoto Tetsuyoshi , Sudoh Rokuro
Published: July 2006

Oxidation of methyl 3-O-benzyl-4,6-O-benzylidene-2-oximino-α-d-arabino-hexopyranoside (5) with trifluoroperoxyacetic acid afforded in 76% yield the corresponding 2-nitro-glucopyranoside (6) which has a twist-boat conformation in chloroform.
Phenolysis of 1,1- and 3,3-Dimethylallyl Chlorides. Rates and Product Distributions
Authors: Takeuchi Ken’ichi , Fujii Yoshinobu , Okamoto Kunio
Published: July 2006

The phenolyses of 1,1- and 3,3-dimethylallyl chlorides were shown by kinetic studies to undergo SN1 solvolysis. The distributions of the products, dimethylallyl phenyl ethers and (dimethylallyl)phenols, supported the mechanism that involves both localized ion-pairs and mesomeric ion-pairs.
A Conversion of 4α-Bromoshionan-3-one into D : B-Friedobacchara-1,5(10)-dien-3-one and A Preparation of D : B-Friedo-bacchar-5(10)-en-3-one
Authors: Tachibana Kazuo , Yamada Sachiko , Yamada Sh\={u}z\={o} , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

A mixture of D : B-friedo-bacchar-5(10)-en-3-one (2) and D : B-friedo-bacchar-5-en-3-one (4), prepared from 4α-bromoshionan-3-one (3) by the known procedures, was converted into a mixture of 2ξ-bromo-D : B-friedobacchar-5(10)-en-3-one (6) and 2ξ-bromo-D : B-friedo-bacchar-5-en-3-one (7) by bromination with pyridinium tribromide. The mixture (6 and 7) was subjected to dehydrobromination to give D : B-friedo-bacchara-1,5(10)-dien-3-one (5). Hydrogenation of the dienone (5) gave D : B-friedo-bacchar-5(10)-en-3-one (2).
Thermally Stimulated Current in Perylene Crystals
Authors: Sano Mizuka , Egusa Fukuji , Akamatu Hideo
Published: July 2006

A single current peak characteristic of thermally detrapped holes was observed at 220 K, the depth of the traps being determined to be 0.50±0.02 eV. This value showed no apparent correlation with the activation energy for photoconduction, 0.18±0.01 eV.
Kinetics of Ion Exchange in the Chelating Resin Dowex A-1
Authors: Matsuzuru Hideo , Wadachi Yoshiki
Published: July 2006

The kinetics of ion exchanges of Ag+, Zn2+ and Cr3+ at extremely low concentrations on the chelating resin Dowex A-1 has been studied by means of finite volume method. The rate of exchanges for both Ag+ and Zn2+ is dependent on the ionic strength, particle size of the resin and reaction temperature. At higher ionic strength (0.1–0.05) the kinetics is controlled by particle diffusion, whereas at lower ionic one (0.01–0.001) film diffusion is predominant. The apparent activation energy obtained is 3.84 kcal/mol for Ag+ and 3.91 kcal/mol for Zn2+. The exchange rate of Cr3+ obeys a first-order rate equation independent of the ionic strength and particle size of the resin. The apparent activation energy is 15.5 kcal/mol. These results support the view that the ratedetermining step of this reaction is chelate formation reaction.
Proton Hyperfine Splittings in the ESR of Some Alkylphosphine Dimeric Radicals
Authors: Iwaizumi Masamoto , Kishi Takashi , Watari Fumio , Isobe Taro
Published: July 2006

The triplet splittings due to protons were observed for the ESR of the dimeric cation radicals of P(CH3)3, P(CH2CH3)3, and PH(CH3)2; they were formed by the γ irradiation of the rigid CH2Cl2 solutions of these alkylphosphines at 77 K. The observed proton hyperfine splittings for the dimer-cation radicals, [(CH3)3P–P(CH3)3]+ and [(CH3CH2)3P–P(CH2CH3)3]+, were assigned to the hyperfine interaction with two of the methyl and with two of the methylene protons respectively, while those for the [(CH3)2HP–PH(CH3)2]+ radical were assigned to the hyperfine interaction with the two P–H protons. In the former two radicals, the rotations of the methyl and the ethyl groups are restricted. The conformations of the methyl and the ethyl groups have been estimated on the basis of the observed proton hyperfine splittings. The P–H protons of the [(CH3)2HP–PH(CH3)2]+ radical have an extremely large isotropic coupling constant of 58 G; it may be attributed to the direct interaction with the unpaired electron in the anti-bonding σ* orbital of the P–P bond.
Studies of Phase Transitions in Cholesteryl Myristate by Means of Simultaneous Measurements of Polarizing Microscopy and Thermal Analyses
Authors: Sasaki Kunihisa Kazuko , Shinoda Takako
Published: July 2006

An improved DTA furnace and sample cell have been used for accurate DTA measurements and clear polarizing microscopic photographs. The photographs, DTA and TTA curves were obtained simultaneously at different heating or cooling rates for solid-smectic, smectic-cholesteric and cholesteric-isotropic liquid phase transitions in cholesteryl myristate.
Competition of the Two Reaction Mechanisms of Maleic Anhydride Formation in Vapor-Phase Oxidation of Butadiene over Supported Molybdena Catalysts
Authors: Akimoto Masamichi , Echigoya Etsuro
Published: July 2006

Vapor-phase oxidation of butadiene, 2,5-dihydrofuran and furan over supported molybdena catalysts has been investigated with reference to the reaction mechanism and the rate-determining step of maleic anhydride formation from butadiene. Formation of maleic anhydride during the oxidation of butadiene was found to follow two reaction mechanisms, (a) via 2,5-dihydrofuran and furan, and (b) via 2,5-dihydrofuran but not via furan. The energy barrier for the addition of oxygen species to adsorbed butadiene or furan is very high, i.e., 28.9 or 21.9kcal/g-mol, respectively, as compared to that for the oxidative dehydrogenation of the intermediate compounds such as 2,5-dihydrofuran. Formation of 2,5-dihydrofuran is rate-determining in these mechanisms during the oxidation of butadiene to maleic anhydride. The second mechanism plays a more important role in maleic anhydride formation at low temperatures, the role of the first mechanism increasing with a rise in the reaction temperature.
Studies of the Coagulation Flotation of Bentonite and Its Application to the Removal of Co2+ Ions and Fission Products, Ce and Eu
Authors: Kobayashi Koichi , Sato Hiroshi , Kachi Kosei , Nakamura Masao , Sasaki Tsunetaka
Published: July 2006

The regions of dispersion, coagulation precipitation, coagulation flotation, and redispersion were determined for aqueous bentonite-cationic surfactant and bentonite-cationic surfactant-polyacrylamide(PAA) systems. The region of coagulation flotation was markedly extended by the addition of PAA to both the lower and higher concentration regions of the cationic surfactant, hexadecyldimethylbenzylammonium chloride(HDBAC), and to the lower concentration region of bentonite. The phenomenon of coagulation flotation was investigated in detail and was applied to the removal of Co2+ ions and nuclear fission products, 144Ce and 155Eu, from an aqueous solution. The composition of the reagents for the maximum efficiency of bentonite flotation corresponded to that of the maximum efficiency of Co2+-ion flotation. The effect of the pH on the flotation efficiency was studied in particular. The maximum flotation efficiency of 96% was obtained at pH 11 for Co2+ ions, 86% at pH 9.7 for 144Ce, and 93% at pH 10.5 for 155Eu. These radioactive elements were almost completely adsorbed on the surface of bentonite particles and were floated with them in the pH region of the maximum flotation efficiency. It was confirmed that Co2+ ions could be floated also from an extremely low concentration (10−9 mol/l) of Co2+ ions with nearly the same efficiency of flotation and with the additives in the same condition. Co2+ ions could also be effectively removed by using the step-by-step flotation, showing as high a flotation efficiency as 99.8%.
Interfacial Layer between a Mercury Electrode and Dilute Aqueous Solutions of Alkali-Metal Chloride at Potentials of the Cathodic Limiting Current Plateau
Authors: Takahashi Katsuo , Tamamushi Reita
Published: July 2006

The electrochemical properties of the interfacial layer between a DME and dilute aqueous solutions of MCl (M: alkali-metal) at the cathodic limiting current plateau were studied by means of impedance measurements at relatively low frequencies (≤250 Hz). From the frequency and potential dependence of the capacitive and the resistive components of the electrode impedance, the following conclusions were obtained concerning the properties of the interfacial layer under the above condition: (i) when the concentration of cations is extremely low in the vicinity of the electrode surface, the impedance behaves as if the conventional double-layer were absent: (ii) the impedance behavior of the present system can be explained by assuming an equivalent circuit which is given by a series combination of the Warburg impedance for the reduction of M+ and the resistance of solution; and (iii) such an interfacial layer is conventionally called “the Nernst double-layer” and its formation is determined by the mass-transport of the reacting species M+.
Transition-metal Complexes of Pyrrole Pigments. XII. Optical and Magnetic Resonance Spectra of the Cobalt(II) and Nickel(II) Complexes of 1,19-Disubstituted Tetradehydrocorrins
Authors: Murakami Yukito , Sakata Kazunori , Tanaka Yasuhiro , Matsuo Tadashi
Published: July 2006

The cobalt(II) and nickel(II) complexes of 1,19-dimethyl- and 1,19-diethoxycarbonyltetradehydrocorrins were prepared by the template reaction as functioned by metal ions from the corresponding 1,19-disubstituted 1,19-dideoxybiladiene-ac’s. The absorption bands appearing in the energy region greater than 15000 cm−1 were attributed to the π→π* transitions within a ligand molecule. The ligand-field bands were observed in the lower energy region (<15000 cm−1) for the cobalt(II) complexes in which cobalt(II) assumes the C2v coordination symmetry: 2A1←2A1, 2A2←2A1,2B2←2A1, and 2B1←2A1 in an increasing order of energy. The vibrational spectra provided evidences for the formation of the tetradehydrocorrin complexes with perchlorate ion as the counter ion. The angular methyl groups placed at the 1- and 19-positions of tetradehydrocorrins showed the abnormally large up-field shift (2.0 ppm) of their proton signal relative to the parent biladiene-ac’s due to the magnetic anisotropy of the adjacent pyrrole rings A and D. For a 1,19-diethyoxycarbonyltetradehydrocorrin complex, the 1,19-substituents were also placed in the shielding zone of the neighboring pyrrole rings. In the case of the cyclized 2,8,12,18-tetra(2-ethoxycarbonylethyl) derivative, the ethyl ester groups of the 2,18-substituents were presumably placed in a conformational space different from that occupied by those of the 8,12-substituents according to the proton NMR behaviors. The parent biladiene-ac which carries ethoxycarbonyl groups at the 1,19-positions caused a up-field shift of its methine (at bridge positions) proton signal upon cyclization due to the loss of electronic conjugation of carbonyl groups with pyrrole rings, in consistent with the vibrational data. The ESR spectra were measured in chloroform-benzene (2 : 1) at 77 K in the presence and absence of pyridine. The cobalt(II) complexes were identified as of low-spin square-planar type with the unpaired electron in the cobalt dz2 orbital. The coordination capability of 2-ethoxycarbonylethyl groups, which are directly bound to the pyrrole rings in the cyclized metal complex system, was also suggested.
The Resonance Energies of Polyacenes and Related Compounds
Authors: Aihara Jun-ichi
Published: July 2006

The resonance energies of polyacenes were determined on the basis of the additive principle of π-bond energies in nonaromatic compounds. The additive components in the total π-energies for these compounds were reasonably estimated from the infinitely large polyacene. The calculated resonance energies appear to be much improved as compared with those calculated by Hess and Schaad.
An Investigation of the endo Product Selectivity in the Diels-Alder Reaction
Authors: Seguchi Kazuyoshi , Sera Akira , Otsuki Yoshinobu , Maruyama Kazuhiro
Published: July 2006

The Diels-Alder reactions of cyclopentadienes with a variety of substituted ethylenes were carried out, and their reaction rates and the endo : exo isomer ratios of the products were determined. It was shown that the faster reaction is characterized by a higher endo isomer distribution and the existence of a linear correlation between the reaction rate and the endo isomer distribution. The results were interpreted in terms of the concept of secondary orbital interaction in the transition state.
Oxygen-accelerated Generation of the Bromocarbenoid Reagent of Zinc from Diethylzinc and Bromoform. Bromocyclopropanes from Olefins
Authors: Miyano Sotaro , Hashimoto Harukichi
Published: July 2006

Oxygen greatly accelerates the generation of the bromocarbenoid reagent of zinc from diethylzinc and bromoform. Olefins, including cyclohexene, cyclooctene, 1-hexene, cis- and trans-2-butene, isobutene, and 2-methyl-2-butene were bromocyclopropanated in yields of ca. 60–85% using a diethylzinc-bromoform-oxygen system. The bromocarbenoid showed high syn-selectivity for the addition to cyclooctene and cis-2-butene. 9-Bromo-9-deutero[6.1.0]nonane was obtained from cyclooctene using CDBr3. Styrene inhibited the formation of the bromocarbenoid reagent and polymerized under the reaction conditions, suggesting a free radical chain mechanism for the formation of the carbenoid reagent.
Synthesis of o-Ethynylcinnamaldehyde
Authors: Ojima J\={u}ro , Kimura Akihiko , Yokoyama Y\={o}ji , Yokoyama Tai
Published: July 2006

A synthesis of o-ethynylcinnamaldehyde(IV) starting from o-ethynylbenzaldehyde(I) by the Wittig reaction is described.
Nonenzymatic Hydrolysis of Adenosine 5′-Triphosphate in Micellar and Reversed Micellar Systems
Authors: Sen\={o} Manabu , Shiraishi Shinsaku , Araki Koji , Kise Hideo
Published: July 2006

The nonenzymatic hydrolysis of adenosine 5′-triphosphate (ATP) in micellar and reversed micellar system was examined as an approach to elucidate the function of ATPase. In aqueous micellar systems an anionic surfactant does not affect the hydrolysis rate, but a cationic surfactant, cetyltrimethylammonium bromide(CTAB), retards the hydrolysis. This deceleration effect is interpreted to be owing to the pH change or accumulation of hydroxide ions at the cationic micellar-water interface which serves as reaction site. In the reversed micellar system where aqueous ATP phase is solubilized in n-hexane by dodecylammonium propionate(DAP), the hydrolysis rate of ATP is enhanced by several times as compared with that in an aqueous system. Addition of Mg2+ or Ca2+ enhances the hydrolysis rate markedly only in the DAP reversed micellar system. The catalytic effect of the DAP reversed micellar system is discussed with respect to the polarity of water phase solubilized in the core of reversed micelles.
Some Considerations on the Electronic Spectra of Cyclic Polyenes
Authors: Basu Sadhan
Published: July 2006

The theoretical prediction of a convergence limit in the electronic spectra of cyclic polyenes is nicely borne out by exerimental findings.
Restricted Rotation Involving the Tetrahedral Carbon. XVII. Isolation of Three “Diastereomeric” Rotamers of a Triptycene Type Compound and Stereoselectivity in the Synthesis
Authors: Yamamoto Gaku , Oki Michinori
Published: July 2006

Three rotameric forms of 2,3-dichloro-9-(1,1-dimethyl-2-phenylethyl)-11,12-bis(methoxycarbonyl)-9,10-dihydro-9,10-ethenoanthracene (3) were isolated as stable entities at room temperature. The structural assignment of the rotamers based on the PMR characteristics. Since the synthesis of 3 produced only the ap form, another reaction involving benzyne was carried out to test the generality of the stereoselectivity. Thus the ap form and the sc form of 2,3-dichloro-9-(1,1-dimethyl-2-phenylethyl)triptycene (4) were prepared separately. Equilibration of isomers of 4 was carried out and the barrier to isomerization was obtained as 36.6 kcal/mol.
Kinetics and Stereochemistry of Alkaline Cleavage of 1,1-Diacetyl-2-arylcyclopropane
Authors: Itoh Osamu , Yamamoto Nobuyuki , Nakano Katsuyuki , Sugita Toshio , Ichikawa Katsuhiko
Published: July 2006

The kinetics and the stereochemistry of alkaline cleavage of several 1,1-diacetyl-2-arylcyclopropanes (1) in ethanol-water mixture are reported. The rates can be expressed approximately by a third order equation, rate=k2[1][OH−]2. With para-substituted derivatives (p-CH3, H, p-Cl and p-Br) of 2-phenyl ring, the reaction constant ρ was obtained as +4.3 by plotting logk2 against normal Hammett σ. At 0 °C, the main products were thermodynamically unstable cis-1-acetyl-2-arylcyclopropanes. The cis to trans ratio in the products decreased with increasing reaction temperature. The reaction mechanism has been discussed in relation to the cleavage reaction of unenolizable acyclic β-diketone. The large ρ value and preferred formation of cis product suggest that the substituent effects of 2-aryl group are transmitted through cyclopropane ring much more effectively to trans direction than to cis direction.
The Chlorination of Norbornene by Metal Chlorides and the Product Isomerization
Authors: Uemura Sakae , Onoe Akira , Okano Masaya
Published: July 2006

The reaction of norbornene with CuCl2, TlCl3·4H2O, PbCl4, SeCl4, SbCl5, and VCl4 in CCl4, CH2Cl2, or CH3CN gave a mixture of nortricyclyl chloride (1), and six isomeric dichloronorbornanes [trans-2,3-(2), exo-2-anti-7-(3), trans-2,5-(4), exo-cis-2,5-(5), exo-cis-2,3-(6), and exo-2-syn-7-(7)], the product distribution depending very much on metal chlorides and reaction conditions. The reactions did not show any participation of a chlorine molecule which may be released from metal chlorides. The ability of SeCl4 and VCl4 to chlorinate olefins was found for the first time. From a synthetic viewpoint CuCl2 was a good reagent for obtaining 2, while TlCl3·4H2O and SbCl5 were recommended for either 3 or 7. The reactions with the following metal chlorides did not give any dichloronorbornanes; SnCl4, BiCl3, TiCl4, FeCl3, NbCl5, TaCl5, and WCl6. It was revealed that isomerization of 2 or 7 to a mixture of 3, 4, and 5 occurred very rapidly by SbCl5 and smoothly by TlCl3·4H2O. The chlorination of norbornene and their products isomerization were mainly explained by assuming a chloronorbornyl cation as an intermediate.
Formations and Reactions of o-Benzoquinone Mono- and Di-imines. I.
Authors: Nogami Takashi , Hishida Tadanori , Yamada Masakazu , Mikawa Hiroshi , Shirota Yasuhiko
Published: July 2006

We have succeeded in obtaining o-benzoquinone monoimine (o-BQMI) and o-benzoquinone diimine (o-BQDI) by oxidizing o-aminophenol (o-AP) and o-phenylenediamine (o-PD), respectively, with freshly prepared lead dioxide at −10 °C in several organic solvents, and also with potassium hexacyanoferrate (III) in an aqueous buffer solution. The formations and reactions of o-BQMI and o-BQDI in aqueous buffer solution were investigated by a stopped flow technique together with a conventional electronic absorption measurements. Both o-BQMI and o-BQDI were formed in the pH range 8–12, and the hydrolysis of o-BQMI to produce o-benzoquinone was found in the pH range 6–8. Both o-BQMI and o-BQDI were found to be unstable at a room temperature to produce 2-aminophenoxazin-3-one (APZ) and 2,3-diaminophenazine (DAP), respectively, as the main products. The formation reactions of APZ and DAP were investigated by observing the spectroscopic course of the reactions in o-BQMI- o-AP and o-BQDI- o-PD system in diethyl ether.
Charge-transfer Intermediate in The Reaction of Thioketone with Nucleophiles
Authors: Ohno Atsuyoshi , Nakamura Kaoru , Uohama Misao , Oka Shinzaburo , Yamabe Tokio , Nagata Shinichi
Published: July 2006

Thiobenzophenone reacts with butyllithium, phenyllithium, and sodium ethoxide in ethanol giving benzhydryl butyl sulfide, benzhydryl phenyl sulfide, and dibenzhydryl disulfide, respectively. On the other hand di-t-butyl thioketone affords 2,2,4,4-tetramethylpentane-3-thiol, 2,2,4,4-tetramethyl-3-phenylpentane-3-thiol, and 2,2,4,4-tetramethylpentane-3-thiol by the reaction with butyllithium, phenyllithium, and sodium ethoxide in ethanol, respectively. Product analyses and tracer experiments with deuteriums have revealed that these reactions proceed through a charge-transfer mechanism.
Reaction of 2,4,6-Tri-t-butylnitrobenzene with Alky Grignard Reagents
Authors: Inagaki Yoshio , Okazaki Renji , Inamoto Naoki
Published: July 2006

Reactions of 2,4,6-tri-t-butylnitrobenzene (1) with alkylmagnesium halides afforded 2,4,6-tri-t-butylaniline (2), N-alkyl-2,4,6-tri-t-butylanilines (3), 6-alkyl-2,4-di-t-butylanilines (4), 4-alkyl-1-hydroxyimino-2,4,6-tri-t-butyl 2,5-cyclohexadienes (5), and 6-alkyl-1-hydroxyimino-2,4,6-tri-t-butyl-2,4-cyclohexadienes (6) depending on the Grignard reagents used. Reduction of the oxime 6 proved to be responsible for the formation of the aniline 4. Comparison of the present reactions with those of 2,4,6-tri-t-butylnitrosobenzene (7) with Grignard reagent, syn-anti-isomzrs of the oxime 6, and the formation mechanisms of the products have been discussed.
Phosphinidenes and Related Intermediates. IV. Reactions of Phosphinothioylidenes with cis- and trans-Stilbene Oxides
Authors: Nakayama Shigenobu , Yoshifuji Masaaki , Okazaki Renji , Inamoto Naoki
Published: July 2006

Phosphinothioylidenes were generated by the reaction of phosphonothioic dichlorides with magnesium. Reactions of phosphinothioylidenes with cis- and trans-stilbene oxides gave 1,3,2-oxathiaphospholane 2-sulfide derivatives (6, 7, 9, and 11) stereospecifically, except for the reaction of phenylphosphinothioylidene with trans-stilbene oxide, along with cis- and/or trans-stilbenes. The formation mechanisms, which involve phenylphosphinothioylidene coordinated by the ethereal oxygen atom, and the conformation of 1,3,2-oxathiaphospholane 2-sulfides were discussed.
Penetration-depth Dependence of Photochemical Conversions in the Dye-sensitized Heterogeneous Photopolymerization of Acrylamide
Authors: Yamase Toshihiro , Ikawa Tsuneo
Published: July 2006

The Amethyst violet-sensitized photolysis of p-tolyl p-anilinobenzenediazo sulfone initiated the polymerization of acrylamide in ethanol-water (9.3 : 0.7, v/v) to yield insoluble polymers. The polymer particles formed scattered the incident 546 nm light, leading to a change in the rate of photopolymerization. Using a 632.8 nm laser beam for viewing the sample at various penetration depths normal to the 546 nm light beam, a new method of determining the penetration-depth dependence of the yield of polymers was presented on the basis of the approximately linear relationship between the optical density at 632.8 nm and the polymer concentration. The method had the advantage that the progress of the photopolymerization, which takes place rapidly, can be easily followed with a high sensitivity below a 2.2% monomer conversion. From an evaluation of the magnitude of both the shadowing and forward scattering arising from the increasing number of polymer particles at various depths, it was confirmed that 546 nm light scattered by polymer particles brought about an effective photopolymerization over a wide range of the depths as a forward-scattering effect. Furthermore, the exposure to the 546 nm beam intensity range from 142 μW/ cm2 to 15.6 μW/ cm2 at sample depths up to 10 mm exhibited equal contributions of shadowing and forward scattering at the depth of ∼1.5 mm.
Hyperconjugative Deuterium Isotope Effects on the Redox Decomposition of Hydroxymercurated 2-Butenes in an Aqueous Solution
Authors: Kosaki Miharu , Shinoda Sumio , Saito Yasukazu
Published: July 2006

The relative magnitude of the isotope effects of the deuterium atoms at the positions hyperconjugative to α- and β-carbons has been determined for the title reaction by monitoring the reaction of 2-butene-1,1,1,3-d4 by PMR. On the basis of our results, the cation character in the transition state is concluded for both of the carbons, in support of the structure proposed previously.
Enthalpies of Combustion of Organic Compounds. III. d-, l- and Dl-Alanines
Authors: Kamaguchi Akeji , Sato Tomoko , Sakiyama Minoru , Seki Syûzô
Published: July 2006

Enthalpies of combustion of d-, l- and Dl-alanines were measured by oxygen static bomb calorimetry. Derived thermodynamic quantities at 298.15 K for d-, l- and Dl-isomers are as follows: ΔEc°=−1619.24±0.58, −1620.26±0.63 and −1617.97±0.50 kJ mol−1; ΔHc°=−1619.86±0.58, −1620.88±0.63 and −1618.59±0.50 kJ·mol−1; ΔHf°=−561.08±0.71, −560.06±0.76 and −562.35±0.65 kJ mol−1, respectively.
The Circular Dichroism Spectra of the β-Cyclodextrin Complex with Naphthalene Derivatives
Authors: Harata Kazuaki , Uedaira Hisashi
Published: July 2006

The circular dichroism spectra of β-cyclodextrin complexes with naphthalene derivatives were investigated. A remarkable difference in the spectra was observed between the 1-substituted naphthalene complex and the 2-substituted naphthalene complex, indicating that the steric effect of substituents on the formation of the complex is so strong that the structures may be different for these complexes. The calculation of the rotational strength by the method of Kirkwood-Tinoco revealed that the structure of the 2-substituted naphthalene complex is an axial inclusion.
Phenylations of β-Nitrostyrene Derivatives with Benzene by the Use of Palladium(II) Acetate
Authors: Yamamura Kimiaki , Watarai Setsuo
Published: July 2006

The phenylations of several β-nitrostyrene derivatives with benzene in the presence of palladium(II) acetate have been studied. The nitro group of the β-nitrostyrenes investigated affects the phenylations very strongly, because of its powerful electron-withdrawing nature, and a high reactivity and regiospecificity were observed.
Synthesis of Sugar Derivatives of N-Alkyl-N-nitrosourea
Authors: Machinami Tomoya , Kobayashi Kazuki , Hayakawa Yoshiki , Suami Tetsuo
Published: July 2006

Thirteen sugar derivatives of N-alkyl-N-nitrosourea have been prepared as follows. The reaction of a sugar amine with alkyl isocyanate gives a sugar derivative of N-alkylurea. When the product is treated with sodium nitrite in aqueous acetic acid, it gives the N-alkyl-N-nitrosourea derivative.
Physico-chemical Studies of the Reversible and Irreversible Phase Transitions in Potassium Ferrocyanide Trihydrate and Its Deuterate Analogue
Authors: Oguni Masaharu , Matsuo Takasuke , Suga Hiroshi , Seki Syûzô
Published: July 2006

Phase transitions of K4Fe(CN)6·3H2O and its deuterate were studied through the measurements of differential thermal analysis curves, heat capacity, volume expansion and Raman spectra. Samples prepared by recrystallization from the aqueous solution were found to be in the metastable phase. The ferroelectric transition temperature between two stable monoclinic phases was determined to be 247.8 K and 252.7 K for the hydrate and deuterate, respectively. The enthalpy and entropy changes of the transition were estimated to be 2592 J mol−1 and 12.41 JK−1 mol−1, respectively, for the hydrate, and 3017 J mol−1 and 14.36 JK−1 mol−1, respectively, for the deuterate. The molecular mechanism of the transition was discussed in terms of entropy change. The transition was also concluded to be of the second order according to Ehrenfest’s criterion. Irreversible transformation of tetragonal to monoclinic phase was observed for the first time for the deuterate as a new type of phase change having a Martensitic nature. These irreversible transformations took place in the temperature region covering 20 K below ca. 232 K and ca. 237 K for the hydrate and deuterate, respectively. The anhydrous salt showed no transformation in the temperature region between 13 K and room temperature.
Nuclear Quadrupole Resonances of Tellurium Tetrachloride and Tellurium Tetrabromide
Authors: Okuda Tsutomu , Yamada Koji , Furukawa Yoshihiro , Negita Hisao
Published: July 2006

The nuclear quadrupole resonances (NQR) due to 35Cl and 81Br in TeCl4 and TeBr4 have been observed and their Zeeman effects have been examined. Each spectrum consists of six resonance lines with equal intensities, which are assigned to the two species of TeCl3+ ions or TeBr3+ ions. The asymmetry parameter of the electric-field gradient is, at most, 5% in each case. The relative orientation among the zero-splitting patterns of six resonance lines is consistent with the crystal structure of TeCl4, which consists of the tetramers of (TeCl3+Cl-)4, as was recently determined by X-ray diffraction analysis. The zero-splitting patterns of the TeBr4 crystal are so similar to those of TeCl4 that the former crystal seems likely to consist of tetramers of (TeBr3+Br-)4 as well. The average ∠X–Te–X bond angles in TeX3+ ions were found to be 95.9° for the chloride and 96.7° for the bromide. The values for the chloride are in good agreement with those obtained by the X-ray analysis. On the other hand, the bond character of the TeX3+ ions in TeX4AlX3 (X=C1, Br) was compared with that of TeX4 from NQR.
A Torsional Braid Analysis of Polymethacrylates, Polyacrylate, Poly(vinyl alcohol), and Their Related Polymers during the Thermal Degradation
Authors: Furusho Noboru , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

The torsional braid analysis (TBA), thermogravimetry, and IR spectroscopy of polymethacrylates, polyacrylate, poly(vinyl alcohol), and their related polymers were carried out in air. The chemorheological properties of these polymers are markedly dependent on their chemical structures. First, the α-hydrogen atom plays an important role. In poly(methyl acrylate), the chemorheological behavior is similar to that of the polymers which have tendency to crosslink, whereas poly(methyl methacrylate) does not show any such behavior. A similar situation was found when comparing poly(acrylic acid) with poly(methacrylic acid). At the same time, the influence of the functional groups was examined. Second, the change in the mechanical properties due to crosslinking becomes more noticeable with an increase in the side-chain length of the methacrylate polymers. Furthermore, in addition to procedures used in the previous work, a new method of kinetic analysis of the heating-rate dependence was carried out in the case of poly(acrylic acid). The apparent activation energies estimated by this treatment are in good agreement with those estimated by other procedures.
Anomalous Phosphorescence of p-Methylacetophenone in Nonpolar Solvent at 77 K
Authors: Tanimoto Yoshifumi , Hirota Noboru , Nagakura Saburo
Published: July 2006

Absorption and phosphorescence spectra were studied for p-methylacetophenone in 3-methylpentane—isopentane mixed solvent at low temperature. From the concentration and temperature dependencies of the absorption spectrum, it is concluded that the monomer-dimer equilibrium exists in the solution of the p-methylacetophenone at low temperature. The phosphorescence of p-methylacetophenone in the mixed solvent at low temperature was found to be composed of two components, with lifetimes of 23 and 42 ms at 77 K. They are ascribed to the π,π* triplet states of the monomer and dimer, respectively.
Several Novel Ru(II) and Ru(III) Complexes Formed by Reduction of [RuO4bipy] and [RuO3phen]2O with Hydroquinone and Methanol
Authors: Ishiyama Toshio
Published: July 2006

The geometrical isomers, cis-dichlovo-trans-(methanol) (hydroquinone) (2,2′-bipyridine)ruthenium(II) and cis-dichlovo-cis-(methanol)(hydroquinone)(2,2′-bipyridine)ruthenium(II), [RuCl2(MeOH)(QH2)bipy] (complex I and II), were synthesized by reduction and substitution reactions of [RuO4bipy] and [RuO2(OH)2bipy] with hydroquinone in hydrochloric acid solution, and methanol. cis-Chloro(hydroquinonato)bis(2,2′-bipyridine)-ruthenium(II), cis-[RuCl(QH)(bipy)2], was obtained from the substitution reaction of complex I or II with 2,2′-bipyridine in methanol, and cis-chloro(hydroquinone)bis(2,2′-bipyridine)ruthenium(II) chloride, cis-[RuCl(QH2)-(bipy)2]Cl, was also obtained from the substitution of cis-trans-[RuCl2(MeOH)(QH2)bipy] in methanol containing hydrochloric acid. cis-Dihydroxobis(2,2′-bipyridine)ruthenium(II),cis-[Ru(OH)2(bipy)2], was obtained by heating an aqueous solution of cis-[RuCl (QH) (bipy) 2]. Trihydroxoaquo (1,10-phenanthroline) ruthenium (III), [Ru(OH)3(H2O)phen] was also synthesized from [RuO3phen]2O and [Ru(OH)3phen]2O by reduction reactions similar to those used for [RuCl2(MeOH)(QH2)bipy]. These complexes were characterized by the infrared, visible and ultraviolet absorption spectra, and also by polarographic and magnetic measurements. The structures are discussed.
Metal Complexes of Amino Acids. VII. The trans(N) and cis(O)cis(N) Isomers of the Type [Co(aa)2phen]X and [Co(aa)2dipy]X
Authors: Yasui Takaji
Published: July 2006

Fourteen complexes of the type [Co(aa)2phen]X and [Co(aa)2dipy]X (where aa is the anion of glycine, β-alanine, l-serine, or l-proline) were newly prepared. Two geometrical isomers (trans(N) and cis(O)cis(N)) for the glycinato and β-alaninato complexes, four geometrical and/or diastereomeric isomers ((+)d- and (−)d-trans(N) and -cis(O)cis(N)) for the l-serinato complexes, and two diastereomers ((+)d- and (−)d-trans(N)) for the l-prolinato complex were separated. These complexes were characterized by absorption, circular dichroism spectra, and 1H and 13C NMR spectra. The absolute configurations of the l-serinato and l-prolinato complexes were assigned as Λ and Δ for the (+)d- and (−)d- isomers, respectively.
Studies of the Mixed Amino Acid Complexes of Cobalt(III). III. Absorption and Circular Dichroism Spectra of Bis(amino acidato)ethylenediamine cobalt(III) and Bis(amino acidato)oxalatocobaltate(III) Complexes
Authors: Matsuoka Nobuko , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Three isomers of cis(O)-bis(l-alaninato)ethylenediaminecobalt(III) perchlorate, four isomers of potassium cis(N)-bis(l-alaninato)oxalatocobaltate(III) and two isomers of potassium trans(N)-bis(l-prolinato)oxalatocobaltate(III) have been prepared, and their configurations have been assigned by absorption and circular dichroism spectra. From analysis of the circular dichroism spectra of about 25 complexes of these types (the aminoacidato ligands are glycinato, l-alaninato, l-serinato and l-prolinato), the configurational and the vicinal circular dichroism curves have been separated and discussed. The vicinal circular dichroism curve shows a pattern characteristic of the absolute configuration of α-aminoacidato ligand and of the geometrical structure of the complex.
A Synthesis of 3-Hydroxy-5-methoxyphenanthro[4,5-bcd]furan
Authors: Horaguchi Takaaki , Shimizu Takahachi
Published: July 2006

3-Hydroxy-5-methoxyphenanthro[4,5-bcd]furan (Ia) was synthesized by the dehydrogenation of 5-methoxy-3-oxo-1,2,3,8,9,9a-hexahydrophenanthro(4,5-bcd)furan (IVa), starting from 8-hydroxy-7-methoxy-1-tetralone (IIb).