bluuebunny/crossref_metadata_2025 huggingface dataset:
Branched-chain Sugars. XI. Synthesis of 2,3,6-Trideoxy-3-C,4-O-dimethyl-3-nitro-d-arabino-hexopyranose (d-Evernitrose)
Authors: Yoshimura Juji , Matsuzawa Masafumi , Funabashi Masuo
Published: July 2006

2,3,6-Trideoxy-3-C, 4-O-dimethyl-3-nitro-d-arabino-hexopyranose was synthesized by the oxidation of methyl α-glycoside of the corresponding 3-amino derivative with m-chloroperbenzoic acid followed by hydrolysis. The 3-amino derivative was synthesized from methyl 4,6-O-benzylidene-2-deoxy-α-d-erythro-hexopyranosid-3-ulose by introduction of the amino-branching function according to the method of Bourgeois, followed by 6-deoxygenation and 4-O-methylation.
Selective Dimerization of Ethylene Catalyzed by Halogenotris-(triphenylphosphine)cobalt(I) Complex-Lewis Acid
Authors: Kawakami Kiyoshi , Mizoroki Tsutomu , Ozaki Atsumu
Published: July 2006

Dimerization of ethylene is highly selectively catalyzed by CoX(PPh3)3 (X=Cl, Br, and I) in the presence of Lewis acid in halobenzene under mild conditions. The catalytic activity is significantly affected by the solvent, bromobenzene being the most effective. The role of BF3·OEt2 seems to be formation of a one-to-one complex of Co(I) and BF3, since the rate of ethylene dimerization attains a plateau on addition of equimolar amount of BF3·OEt2. The isomerization of 1-pentene is enhanced by addition of molecular hydrogen or ethylene to the catalyst system. The isotopic scrambling between C2H4 and C2D4 takes place faster than dimerization. The results are in line with hydridocobalt intermediate formed by the oxidative addition of ethylene to Co(I) complex.
Synthesis of 6-O-Acyl Derivatives of Immunoadjuvant Active N-Acetylmuramyl-l-alanyl-d-isoglutamine
Authors: Kusumoto Shoichi , Okada Satoshi , Yamamoto Koji , Shiba Tetsuo
Published: July 2006

Seven acyl derivatives of N-acetylmuramyl-l-alanyl-d-isoglutamine, which had previously been shown to be a minimum structure required for the immunoadjuvant activity, were synthesized in order to evaluate the significance of lipophilicity on the adjuvant activity and on the possible antitumor effect. Among them, are included 6-O-docosanoyl, stearoyl, lauroyl, octanoyl, butyryl, acetyl, and 4,6-di-O-acetyl derivatives. Some of these compounds were found to serve an improvement in the administration method to living body.
Studies of Peptide Antibiotics. XXXIX. Syntheses of Gramicidin S Analogs Containing l-Histidine in Place of l-Ornithine
Authors: Nonaka Kazuhiko , Sato Kazuki , Terada Shigeyuki , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

Two analogs of gramicidin S, [2-l-histidine]-gramicidin S (14) and [2,2′-di-l-histidine]-gramicidin S (19), were synthesized to compare the biological role of δ-amino groups in l-ornithine residues in the antibiotic with that of weakly basic imidazolyl groups in l-histidine residues. Compound 14 exhibited identical activity to that of gramicidin S, but 19 was only 1/8 as active. The optical rotatory dispersions of these analogs and gramicidin S were nearly the same: molecular conformation of these peptides must be very similar. Compounds 14 and 19 showed esterolytic activity against p-nitrophenyl acetate. The activity of 14 was higher than that of imidazole, 14 being more active than 19.
The Sensitized Photooxidation of Cycloheptatriene (Tropilidene). Isolation and Thermal Isomerization of (4π+2π) Cycloadduct, 8,9-Dioxabicyclo[3.2.2]-2,6-nonadiene, and Preparation of Tropone
Authors: Asao Toyonobu , Yagihara Morio , Kitahara Yoshio
Published: July 2006

The sensitized photooxidation of cycloheptatriene (tropilidene) in methanol afforded (4π+2π) cycloadduct; 8,9-dioxabicyclo[3.2.2]-2,6-nonadiene (1), 6-hydroxy-2,4-cycloheptadienone and 6-oxoheptadienal presumably derived from (6π+2π) cycloadduct, and small amounts of tropone and benzaldehyde. Mechanism of their formation are discussed. It was found that the treatment of the photooxidation mixture with trie thy lamine afforded tropone in about 50% yield. Thermal isomerization of 1 in refluxing xylene afforded cis-3,9-dioxatricyclo-[6.1.0.02.4]-5-nonene, 8-oxabicyclo[5.1.0]-4-octen-3-one and 4-hydroxy-2,6-cycloheptadienone.
A Convenient Method for the Synthesis of Dihydropyranobenzopyrandiones and Their Sulfur Analogs
Authors: Merchant J R , Dike S Y
Published: July 2006

A general and convenient synthesis is described of a number of 2,3-dihydro-4H,5H-pyrano[3,2-c][1]benzopyran-4,5-diones and 2,3-dihydro-4H,5H-pyrano[2,3-b][1]benzothiopyran-4,5-diones. It involves the condensation of 4-hydroxycoumarin derivatives and their thioanalogs with different α,β-unsaturated acids in the presence of PPA. Assignments of the structures in both the cases are based on analytical and spectroscopic evidence.
Studies on the Cannabinoid Field: Synthesis of New Cannabinoids from 4-Hydroxycoumarin and 4-Hydroxythiocoumarin by Pyridine-catalysed Condensation of Citral and Citronellal
Authors: Dike S Y , Merchant J R
Published: July 2006

The reaction of 4-hydroxycoumarin and 4-hydroxythiocoumarin with citral in basic as well as acidic conditions led to the formation of tetrahydrocannabiol derivatives. With citronellal, the above hydroxycoumarins afforded the corresponding hexahydrocannabiol derivatives in moderate yields. The structures and the stereochemistry of the compounds obtained are established on the basis of spectral-analytical evidence.
Kinetics and Mechanism of the Oxidation of the Esters of Mandelic Acid by Lead Tetraacetate
Authors: Banerji Kalyan K , Banerjee Sudheer K , Shanker Rama
Published: July 2006

The oxidation of eight esters of mandelic acid by lead tetraacetate in benzene solution has been studied. The product of the oxidation is the corresponding phenylglyoxylic ester. The oxidation is of first order with respect to the oxidant and second order to the ester. The reaction is catalysed by pyridine, the catalysed reaction being first order in pyridine. In the presence of pyridine, the reaction is first order with respect to each the oxidant and the ester. The oxidation of ethyl α-deuteriomandelate indicated a kinetic isotope effect. The activation parameters have been determined. The results have been interpreted in terms of a slow decomposition of lead tetraalkoxide derivative involving heterolysis of Pb–O bond.
Intermolecular Chelate Linkage Isomerism of the Hydroxyimino Group in the Nickel(II), Copper(II), and Palladium(II) Complexes of Quadridentate Schiff-base Ligands
Authors: Dixit N S , Sudha B P , Patel C C
Published: July 2006

The C-nitrosation of bivalent quadridentate β-imino ketone complexes of nickel(II), copper(II), and palladium(II), with nitrosating reagents has been investigated. The chemical analysis and spectroscopic results reveal that one of the α-CH groups of the coordinated lignad undergoes selective nitrosation forming mono(hydroxyimino) derivative. The hydroxyimino group introduced coordinates through either N- or O- atom to metal(II) by dislodging the carbonyl group already coordinated. This gives rise to two linkage isomers, one with N-bonded and the other with O-bonded hydroxyimino group in the case of nickel(II) (except for 1d) and palladium(II), and a single isomer with O-bonded hydroxyimino group in copper(II) complexes. The isomers obtained from 1b and 1i have been separated by column chromatography. In chloroform each of the isomers of nickel(II) isomerizes to give an equilibrium mixture of two isomers, but not those of copper(II) and palladium(II).
Reactivity of Organic Ions by Chemical Ionization Mass Spectrometry. II. Chemical Ionization Mass Spectra of Alkylbenzenes with Methane by Using a Quadrupole Mass Spectrometer
Authors: Iseda Kozo
Published: July 2006

The titled spectra have been determined at 75 °C. The (M+H)+ ion intensities for methylbenzenes decrease linearly with the number of methyl substituents. The (M+H)+ ion intensities for dialkylbenzenes decrease in the order o->m->p-, while those of trimethylbenzenes decrease in the order 1,2,3-> 1,3,5->1,2,4-, and those of tetramethylbenzenes decrease in the order 1,2,3,4->1,2,3,5->1,2,4,5-.
Reactive Troponoids and o-Aminophenol. I. Synthesis of Cyclohepta[b][1,4]benzoxazine
Authors: Nozoe Tetsuo , Okai Harue , Someya Taichi
Published: July 2006

Cyclohepta[b][1,4]benzoxazine and 2-(o-hydroxyanilino)tropone were obtained by the reactions of 2-chloro- and 2-methoxytropone with o-aminophenol. A similar reaction with o-methoxylaniline gave 2-(o-methoxyanilino) tropone and 1-(o-methoxyanilino)-7-(o-methoxyphenylimino)-1,3,5-cycloheptatriene. The chemical and physical properties of cyclohepta[b][1,4]benzoxazine were discussed.
The Radiolysis of Binary Mixtures of Tetrahydrofuran with Benzene, Thiophene, Pyridine, and Nitrobenzene
Authors: Matsui Masao , Imamura Masashi
Published: July 2006

Binary mixtures of tetrahydrofuran (THF) with benzene, thiophene, and nitrobenzene were subjected to radiolysis with γ-rays. The THF–benzene mixture was also irradiated with 28.6 MeV 4He- and 90.9 MeV 12C-ions. For THF–benzene mixtures, similar deviations of G(H2) from the mixture law were observed for all the radiolyses; these results are regarded as being due to energy transfer from THF+, the precursor of hydrogen, to benzene. The total ionization yield of THF was calculated as 3.0–3.3 in G-units, irrespective of radiation and additives. This is on the basis of Hardwick’s procedure, in which the deviations of G(H2) are divided by the efficiency of the energy transfer. This result also indicates that the total ionization yield is independent of the nature of radiation, whose LET range is from 0.02 to 49.2 eV/Å.
The Crystal and Molecular Structure of N-Carboxy-γ-benzyl-l-glutamate Anhydride
Authors: Kanazawa Hitoshi , Kawai Tohru , Ohashi Yuji , Sasada Yoshio
Published: July 2006

The structure of N-carboxy-γ-benzyl-l-glutamate anhydride has been determined by X-ray analysis. The crystal is orthorhombic; space group, P212121; Z=4 with a=7.766(1), b=27.470(4), and c=5.948(1) Å. The structure was deduced by the direct method and refined to a final R value of 0.057 for 1504 observed reflections by the block-diagonal least-squares method. The hydrogen bond is formed between the imino group and the carbonyl group of the side chain. The dimension of the five-membered ring is affected by the intermolecular hydrogen bond as compared with the crystal structures of the other N-carboxy anhydrides of α-amino acid.
The Crystal and Molecular Structure of N-Carboxy-l-leucine Anhydride at −70°C
Authors: Kanazawa Hitoshi , Kawai Tohru , Ohashi Yuji , Sasada Yoshio
Published: July 2006

The crystal structure of N-carboxy-l-leucine anhydride has been determined by means of X-ray. The crystal is orthorhombic; space group, P212121; Z=4 with a=6.527(1), b=23.920(4), and c=5.527(1) Å. The structure was deduced by the direct method and refined to the final R value 0.049 for 624 observed reflections by the block-diagonal least-squares method. The N-carboxy anhydride rings are arranged in a layer form sandwiched by hydrophobic side chains. The highest polymerizability of this compound in the crystalline state is due to the sandwich structure.
Potential of Hydrocarbons for Photochemical Conversion of NO to NO2
Authors: Washida Nobuaki , Inoue Gen , Akimoto Hajime , Okuda Michio
Published: July 2006

The factor F, the number of NO molecules which are converted photochemically into NO2 when one hydrocarbon molecule is consumed, was determined for fourteen different hydrocarbons in the photochemical oxidation process. Experiments were carried out in a 67 dm3 Pyrex reaction chamber in which a mixture of hydrocarbon, NO, H2O, and air was irradiated by a xenon short arc lamp. In the range from low to middle conversion, hydrocarbons and NO decayed nearly exponentially, NO being converted into NO2. The observed value of F was approximately two for most of the hydrocarbons studied. The value is in line with the long chain mechanism involving OH radicals predicted by Heicklen et al. Only m-xylene gave a larger F value. Reaction sequences of the long chain mechanism caused by OH radicals were discussed, a generalized kinetic model for the chain mechanism being proposed. This will be useful for the atmospheric modeling of photochemical smog.
Solubility and Diffusion Coefficient of Sulfur in Copper
Authors: Fueki Kazuo , Ouchi Yasumasa
Published: July 2006

The solubility and diffusion coefficient of sulfur in copper were determined by a new method, wherein a thin copper(I) sulfide film was formed on the surface of a copper specimen and the decrement of its thickness after diffusion annealing was determined coulometrically. It was found that the solubility Cs could be represented by

logCs(ppm)=−0.616−0.410(104⁄T),

and the diffusion coefficient is given by

D=0.834×exp(−40900⁄RT)cm2s−1.
Molecular Structure and Conformation of Ethyl Methyl Sulfide as Studied by Gas Electron Diffraction
Authors: Oyanagi Kazuko , Kuchitsu Kozo
Published: July 2006

The bond distances (rg) and angles (rα structure) in ethyl methyl sulfide have been determined by gas electron diffraction as follows: average of C(methyl)–S and C(methylenc)–S=1.813±0.004 Å, C–C=1.536±0.008 Å, C–H=1.111±0.008 Å, ∠C–S–C=97.1±1.1°, ∠S–C–C=114.0±0.5°, ∠H–C–H=109.6±1.4°, where uncertainties represent estimated limits of experimental error. The two C–S lengths have been estimated independently with the aid of the rotational constants for the trans conformer reported by Hayashi et al.: C(methyl)–S=1.806±0.027 Å, C(methylene)–S=1.818±0.027 Å. The dihedral angle for the gauche conformer (66±9°) and the relative abundance of the trans and gauche conformers in the gas phase at 20 °C, nt⁄(nt+ng)=0.25±0.15, have also been determined.
Correlation between Relative Sensitivities for Electron Capture Detector and Chemical Structure of Aromatic Halogeno and Nitro Compounds
Authors: Hattori Yukikazu , Kuge Yoshio , Nakagawa Shigeru
Published: July 2006

Relative sensitivities of an electron capture detector (ECD, 63Ni) for aromatic halogeno and nitro compounds were measured at detector temperatures of 230, 290, and 320 °C. The effects of various substituents on the sensitivity of ECD were determined. A good correlation was recognized between the relative sensitivities of ECD and the positions of substituents for aromatic chloro, bromo, and nitro compounds. The plotted logarithm values of ECD sensitivities for aromatic chloro and bromo compounds vs. Hammett’s σ values of various substituents are not linear, but the plots for aromatic nitro compounds follow a straight line. Modified σ values (σH) were determined on the basis of the relative sensitivities of aromatic chloro compounds. Plots of aromatic chloro, bromo, and nitro compounds vs. σH values gave straight lines. The temperature dependence of electron capture coefficients for these compounds was determined using D.C. mode. The electron capture spectra obtained are similar to those using pulsed mode.
Studies of Inorganic Ion Exchangers. II. Effects of Sulfuric Acid on the Synthesis of Ti(HPO4)2·0–1/2H2O
Authors: Kobayashi Etsuro
Published: July 2006

In order to develop an inorganic ion exchanger for industrial use, sulfuric acid has been added to the reaction system of amorphous titanium(IV) phosphate and phosphoric acid. The effects of the additive on the formation of titanium(IV) hydrogenphosphate, a compound observed to have ion exchange affinities towards K+ and Cs+, have been investigated. Ti(HPO4)2·0–1/2H2O has been synthesized using the sulfuric acid solution of TiOSO4, an intermediate in the production process of titanium dioxide. The addition of sulfuric acid to phosphoric acid and a resulting mole ratio of H2SO4/H3PO4 greater than 0.14, produced a borderline in the formation of the monohydrate and hemihydrate within the temperature range of 148–155 °C Titanium(IV) hydrogenphosphate crystallized as fine particles (1–3 μ) by the double decomposition between the sulfuric acid solution of TiOSO4 and phosphoric acid. The X-ray diffraction pattern of the product obtained using the sulfuric acid solution of TiOSO4 above 160 °C compared favourably with that of the hemihydrate already reported. The composition was shown by the formula of Ti(HPO4)2·0–1/2H2O. In the X-ray diffraction pattern of Ti(HPO4)2·0–1/2H2O, two characteristic diffraction lines appeared at 11.6 and 9.21 Å; thus it has been assumed that the product is not a pure crystallite but a mixture of two or more species.
Solubility of Hexaamminenickel(II) Complexes in Aqueous Ammonia Solution and the Thermal Decomposition of Ammine Complexes of Nickel(II)
Authors: Sato Tsugio , Suda Takeshi , Uchida Hideki , Okabe Taijiro
Published: July 2006

The solubility of hexaamminenickel(II) complexes in aqueous ammonia solution (0 to 37 g-free NH3/100g-solv.) was investigated at temperatures 0–55 °C. It rapidly decreases with increase in free ammonia concentration but increases with rise in temperature. Hexaamminenickel(II) carbonate, sulfate, and chloride are slightly soluble at ammonia concentration above 30 g-free NH3/100 g-solv., but nitrate is considerably soluble even at ammonia concentration of 35 g-free NH3/100 g solv. The thermal decomposition of ammine complexes of nickel(II) was also investigated by means of TG and DTA under a streaming nitrogen gas atmosphere. Ammine complexes of nickel(II) decompose as shown in the following, the reaction orders and activation energies for steps a, b, c, and d being 0.5, 1.5, 1.0, and 0.5, and 16.5, 38.8, 25.3, and 79.4 kcal/mol, respectively.

(Remark: Graphics omitted.)

X-Ray diffraction data for [Ni(NH3)6]Cl2·0.5H2O, [Ni(NH3)6](NO3)2, [Ni(NH3)5]SO4·H2O, and [Ni(NH3)2]SO4 powder are given.
Inter- and Intramolecular Rhodium-Rhodium Interactions in Bis-(bidentate isocyanide)rhodium(I) Hexafluorophosphates
Authors: Kawakami Katsuhiko , Okajima Masaki , Tanaka Toshio
Published: July 2006

The reaction of [RhCl(1,5-C8H12)]2 with the stoichiometric amount of bidentate isocyanide followed by metathesis affords complexes of the types [Rh(L–L)2]PF6 (L–L=CN(CH2)8NC (1), CN(CH2)7NC (2)) and [Rh2(L–L)4](PF6)2 (L–L=CN(CH2)6NC (3), CN(CH2)4NC (4)). The electronic spectra at various concentrations reveal that in dilute solutions 1 and 2 exist as monomers with chelating isocyanides, while 3 and 4 form dimers with bridging isocyanides through intramolecular rhodium–rhodium interactions as the smallest unit. On the other hand, in concentrated solutions 1 and 2 form dimers and 4 tetramers through intermolecular Rh–Rh interactions.
The Crystal Structures of Bis(cis-1,3-diaminocyclohexane)palladium(II) Chloride and Its Platinum(II) Analogue
Authors: Kamisawa Keiko , Matsumoto Keiji , Ooi Shun’ichiro , Kuroya Hisao , Saito Reiko , Kidani Yoshinori
Published: July 2006

The structure of bis(cis-1,3-diaminocyclohexane) palladium(II) chloride has been determined from X-ray diffraction data collected by the counter method. The crystal is orthorhombic with space group Pnnm, a=17.728(5), b=6.418(4), c=6.914(2) Å, and Z=2. The crystal structure has been determined by Patterson and Fourier techniques and refined by a least-squares method to R=0.026 for 1151 independent reflections for which Fo2>3σ(Fo2). The Pd atom has a planar coordination of 4N atoms and the complex cation has a crystallographically imposed C2h symmetry, the two cis-1,3-diaminocyclohexane ligands being related to each other by a two fold axis. The six-membered chelate ring (Remark: Graphics omitted.) is of the envelope conformation. The structural features of the ligating cis-1,3-diaminocyclohexane have been described. The crystal of bis(cis-1,3-diaminocyclohexane)platinum(II) (orthorhombic, a=17.727(8), b=6.371(3), c=6.965(2) Å) was found to be isomorphous with that of the palladium analogue.
Constituents of the Essential Oil of Chrysanthemum japonense. Nojigiku Alcohol and Its Acetate
Authors: Uchio Yasuto
Published: July 2006

The essential oil of Chrysanthemum japonense has been analyzed to isolate a new monoterpenoid named nojigiku alcohol together with its acetate, the structure of which has been elucidated as (5R)-2,2-dimethyl-3-methylenebicyclo[2.2.1]heptan-5-ol. In addition, fifteen monoterpenoids including (+)-α-pinene, (+)-camphene, β-pinene, sabinene, 1,8-cineole, p-cymene, filifolone, (+)-chrysanthenone, (+)-camphor, (+)-borneol, (−)-cis-and (+)-trans-chrysanthenyl acetate, cis- and trans-carveyl acetate, (+)-bornyl acetate and nine sesquiterpenoids including α-copaene, β-elemene, β-caryophyllene, germacrene-D, γ-cadinene, calamenene, β-caryophyllene oxide, T-muurolol and α-cadinol were identified in the essential oil.
Carboxylation of Olefins with Carbon Monoxide Using Various Strong Acids–H2O–Group 1B Metal Carbonyl Catalyst Systems
Authors: Yoneda Norihiko , Fukuhara Tsuyoshi , Takahashi Yukio , Suzuki Akira
Published: July 2006

Carboxylation of 2,4,4-trimethyl-1-pentene and 1-octene with carbon monoxide was studied in the presence of various strong acids–H2O–Cu(I) carbonyl catalyst systems in an attempt to find a practical method for the preparation of carboxylic acids. The reaction takes place smoothly at room temperature to give tertiary acids in higher yields than that with the use of sulfuric acid. The procedure is preferable for the ready separation of products from the catalyst layer without quenching by water.
Modification of Aminocyclitol Antibiotics. 6. Preparation of 5-Deoxykanamycin B
Authors: Suami Tetsuo , Nishiyama Shigeru , Ishikawa Yasuhide , Umemura Eijiro
Published: July 2006

Aminocyclitol antibiotic kanamycin B has been modified as regards the aminocyclitol moiety by removing a hydroxyl group on C-5. 5-Deoxykanamycin B thus obtained was tested against several microorganisms. The structure of 5-deoxykanamycin B was established by mass and 13C NMR spectrometry. 5,6,3′,4′-Tetradeoxyneamine was prepared as a reference compound for 13C NMR spectrometry.
Synthesis of 11-Methyl- and 11,11-Dimethylprostaglandins via the Wittig Reaction of α-Dienol
Authors: Inoue Kenji , Ide Junya , Sakai Kiyoshi
Published: July 2006

The key intermediates for 11-methyl- and 11,11-dimethylprostaglandins corresponding to Corey’s lactone were synthesized via the Wittig reaction of dimethyl 2-substituted-4,5-dioxocyclopentane-1,3-dicarboxylate with stable ylides. 11,11-Dimethylprostaglandin E2 was then synthesized.
Coordination of Alkanethiolate Anion to Ruthenium(II) Carbonyl Complex of Octaethylporphine: Model for Carbonyl Adduct of Cytochrome P-450
Authors: Ogoshi Hisanobu , Sugimoto Hiroshi , Yoshida Zen-ichi
Published: July 2006

Absorption, infrared, and 1H-NMR spectra of the ruthenium(II) octaethylporphine carbonyl complex [Ru(II)OEP·CO] were studied in the presence of alkanethiolate anion (−SR) as a model system for the reduced cytochrome P-450 carbonyl complex. The 1H-NMR spectra reveal that alkanethiolate anions coordinte toa the central metal atom of Ru(II)OEP·CO as the sixth ligand. The hexaccordinated complex [Ru(II)OEP·CO·−SR] has anomalous features as compared with the pentacoordinated complex [Ru(II)OEP·CO]: (1) the Soret band is splitted into two peaks, one in the near UV 363–365 nm region and the other in the 419–428 nm region, (2) the carbonyl stretching frequency is shifted by 25 cm−1 to lower wave number, (3) the proton signals of porphyrin ligand are shifted to higher magnetic field. Similarity of absorption and infrared spectra of the hexacoordinated complex to those of the reduced cytochrome P-450 carbonyl complex supports the axial ligation of the cysteinate to the central iron atom of the heme-proteins. The low wave number shifts of carbonyl stretching vibration and high field shifts of protons in the 1H-NMR spectra suggest the charge transfer interaction from 3p lone pair electrons of sulfur atom of alkanethiolate anion to the central metal and/or the porphyrin ligand.
The Synthesis of Neobavaisoflavone and Related Compounds
Authors: Nakayama Mitsuru , Eguchi Shizuko , Hayashi Shûichi , Tsukayama Masao , Horie Tokunaru , Yamada Toshihide , Masumura Mitsuo
Published: July 2006

The condensation of 7-benzoyloxy-4′-hydroxyisoflavone with 2-methyl-3-buten-2-ol gave 7-benzoyloxy-4′-hydroxy-3′-(3-methyl-2-butenyl)isoflavone. The hydrolysis of the alkylated isoflavone with dilute alkali afforded neobavaisoflavone [7,4′-dihydroxy-3′-(3-methyl-2-butenyl)isoflavone], which was then converted into isoneobavaisoflavone on heating with formic acid. 7-Benzyloxy-4′-hydroxyisoflavone was condensed with 2-methyl-3-buten-2-ol to give a chroman derivative, which was then converted into isoneobavaisoflavone by hydrolysis. 3′-(3-Methyl-2-butenyl)-5,7,4′-trihydroxyisoflavone was also synthesized from 7-benzoyloxy-5,4′-dihydroxyisoflavone in a similar manner.
1,3-Dipolar Cycloadditions to Bicyclic Olefins. III. The Effects of Aromatic Solvents on the exo/endo Product Ratios for the 1,3-Dipolar Cycloadditions of Nitrile Oxides to Norbornadienes
Authors: Taniguchi Hisaji , Imoto Eiji
Published: July 2006

When no hydrogen-bonded complex is formed between the precursors (α-chloro-α-hydroxyiminoacetophenone (5a) and α-chloro-α-hydroxyiminoacetone (5b)) of nitrile oxides (phenylglyoxylonitrile oxide (2a) and methylglyoxylonitrile oxide (2b)) and norbornadienes(2,3-bis(methoxycarbonyl)norbornadiene (1) and norbornadiene (6)) in solvents, the exo/endo product ratios for the cycloadditions of 2a and 2b to 1 or 6 increase or decrease with increasing temperature. When the hydrogen-bonded complex between 5a and 1 is formed in a solvent cage, however, the ratio keeps a constant value until the temperature is elevated up to a certain temperature, at which the ratio jumps up. After the jumping, the ratio has another constant value, regardless of the temperature. Similar results are obtained in the cycloaddition of 2b to 1 in the aromatic solvents used.
Electrolytic Dissolution and Deposition of Overpotentials of Tantalum in KCl Melts
Authors: Nakagawa Ippei
Published: July 2006

As part of electrochemical studies on tantalum, the electrolytic dissolution and deposition of solid tantalum in molten salt were studies by measuring its overpotentials in a steady state. The measurements were carried out using the dc current polarization technique in the concentration range of 2.00×10−4–2.79×10−1 mole fraction at temperatures between 775 and 875 °C. The kinetic parameters (the exchange current densities, the transfer coefficients, the kinetic averaged valences, and the apparent activation energies) were determined for the anodic and the cathodic reactions in the Tafel region. The over-all reaction was indicated as:

(m1+m2)Ta2++(2m1−2m2)e\ightleftarrowsm1Ta0+m2Ta4+

The Ta2+ ion was previously supposed not to form a complex ion; the Ta4+, however, was a complex ion which decomposed at above 850 °C.
Pore Structure of Iron Oxides
Authors: Nagao Mahiko , Yokota Yasuhiro , Morimoto Tetsuo
Published: July 2006

The pore structure of iron oxides, subjected to oxidation into α-Fe2O3 as well as reduction into Fe3O4, was investigated by means of the t-method. The results show that the reduction is accompanied by the formation of slit-shaped pores, width 14 Å, open at both ends.
Syntheses and Properties of gem-Diolatotriarylantimony(V)
Authors: Ouchi Akira , Ebina Fujio , Uehiro Takashi , Yoshino Yukichi
Published: July 2006

Titled compounds of the general formula R3Sb(R′R″CO2) have been prepared, where R=phenyl, p-tolyl or p-chlorophenyl, R′,R″=CF3,CF3; CF3,H; or CCl3, H. From the infrared spectra and 1H-NMR data, the gem-diolato group appears to bond to the antimony bidentately through two oxygen atoms, as in the 1,1,1-trifluoro-4-oxo-2,2-pentanediolato complex of triarylantimony(V).
Synthesis and Characterization of Copper Complexes with Schiff Bases Derived from 2-Thiophenealdehyde and Alkylamines
Authors: Kuma Hiro , Motobe Kyoji , Yamada Shoichiro
Published: July 2006

Copper(I) and copper(II) complexes with Schiff bases derived from 2-thiophenealdehyde and alkylamines were prepared. Probable structures of these complexes are discussed mainly on the basis of electronic and infrared spectra and magnetism.
The Configuration of 17-Ethyl-3β-hydroxyetiojerva-5,12,17(20)-trien-11-one and Related Compounds
Authors: Murai Akio , Sasamori Hiroshi , Masamune Tadashi
Published: July 2006

The title compound, one of the most important starting materials for the synthesis of C-nor-D-homosteroid and normal steroid hormones, was determined to possess (E)-configuration at the 17,20-double bond on the basis of chemical and spectral evidence.
The Reduction of Fluorenone Azine with Lithium Aluminum Hydride
Authors: Eda Norio , Minabe Masahiro , Suzuki Kazuo
Published: July 2006

The title reaction yielded fluorenone 9-fluorenylhydrazone and 9,9′-azo(9,9′-bifluorenyl), accompanied by some fragmentary compounds.
Catalytic Activities of Salicylaldehyde Derivatives. V. Syntheses and Catalytic Activities of Some Trimethylammonio Derivatives of Salicylaldehyde in the Racemization of l-Glutamic Acid
Authors: Ando Makoto , Emoto Sakae
Published: July 2006

(3-Formyl-2-hydroxyphenyl) trimethylammonium (2) and (3-formyl-4-hydroxyphenyl)trimethylammonium salts (3) have been prepared from the corresponding 3- and 5-nitrosalicylaldehydes via the 3- and 5-(dimethylamino)salicylaldehydes. The catalytic activities of 2, 3, and the (2-formyl-3-hydroxyphenyl)trimethylammonium salt have been studied at pH 10 and at 80 °C in the presence of copper(II) ion.
Oxidation of Thujopsene with Thallium Triacetate in Acetic Acid
Authors: Sekizaki Haruo , Ito Masaaki , Inoue Shoji
Published: July 2006

Oxidation of thujopsene with thallium triacetate in acetic acid at room temperature gave a stereospecifically ring-contracted ketone (3) in 76% yield, whereas oxidation at 50 °C afforded an allylic oxidation product in 72% yield. The configuration of 3 was estimated by the NMR spectrum of a compound derived from it.
A New Route to o-Methylthiomethylated Phenols by Use of S,S-Dimethylsulfilimines
Authors: Yamamoto Tamotsu , Okawara Makoto
Published: July 2006

As convenient intermediates to introduce methyl groups into the o-positions of phenols, o-methylthiomethylphenols (o-MTM-phenols) were prepared in high selectivity and moderate yield by the reaction of phenols with sulfilimines such as S,S-dimethyl-N-(2,4-dinitrophenyl)- and S,S-dimethyl-N-tosylsulfilimines.
ESR Study on Molecular Alignment of Various Nitroxides in a Nematic Liquid Crystal
Authors: Tanaka Hisao , Kuwata Keiji
Published: July 2006

Various nitroxides with characteristic molecular shapes were studied by ESR spectroscopy to determine the relation between the molecular shape and the ordering in the nematic phase. The hyperfine splitting shifts upon going from the nematic to the isotropic phase and the relative widths of the nitroxyl nitrogen hyperfine lines were examined. Together with an estimate of the molecular dimensions, these results revealed that the ordering properties in three types of nitroxides(each of which has its elongated molecular axis along one of the three principal axes of the nitroxyl nitrogen dipolar tensor) can all be understo od well in terms of the slender molecular shape. This led to the deduction that the Saupe-type anisotropic induced dipole-dipole interaction between the overall molecule of nitroxide and the nematic molecule is superior to the local interaction between the substituent moieties of nitroxide and nematic molecule. The dipolar anisotropy of the β-proton of nitroxide was evaluated to be 3 G.
Far-infrared Reflection Spectra, Raman Spectra and Lattice Vibrations of CsMgCl3 and CsCaCl3
Authors: Morioka Yoshiyuki , Nakagawa Ichiro
Published: July 2006

Far-infrared reflection spectra of single crystals of CsMgCl3 and CsCaCl3 have been measured, and the frequencies of transverse and longitudinal modes of infrared active vibrations have been determined using Kramers-Kronig relation. For CsMgCl3 a measurement of polarized Raman spectra has been made. A normal coordinate analysis of the optically active lattice vibrations has been performed, in which the rigid ion model for long range Coulomb interactions and the central force field including the 1st differential coefficients of the pair-wise potential functions have been used. The obtained short range force constants K(Mg–Cl) and K(Ca–Cl) are 0.715 and 0.63 mdyn/Å, respectively, which indicate that some amount of covalent character exists in the Mg–Cl and Ca–Cl bonds.
The Application of Mathematical Programming in Theoretical Chemistry. I. Saddle-point-search Method Applied to a H3 Molecule
Authors: Yoneda Yukio
Published: July 2006

A new method to find the activated state of a reaction without preparing its potential energy surface was proposed and proved useful with the example of a H3 molecule. The first and the second derivatives of the total energy, with respect to every cartesian coordinate of a H3 molecule, were calculated by means of a perturbation method employing a modified EHMO. First, the bottom of the valley in the potential energy surface leading to the saddle point is sought with the aid of the quadratic approximation on the superplane on which the maximum curvature at the representative point lies. Second, the ascending path is determined to be the reverse of the steepest decending path according to the principle of microscopic reversibility. By repeating these procedures, the activated state was found without preparing the potential energy surface. The classical activation energy thus found was 8.8 kcal/ mol, which is in good agreement with the experimental values.
Absolute Intensity Measurement of Infrared Absorption by the Use of CO2 Laser Source
Authors: Suzuki Tetsuo , Fujiyama Tsunetake
Published: July 2006

The absolute infrared absorption intensities have been measured for the QR0(0) line (ν3 fundamental) of methyl fluoride and the RR8(9) line (ν6 fundamental) of methyl iodide by the use of CO2 laser lines of P(16) and P(8), respectively. The observed intensities, Γ, were: 12500±4300 cm2·mol−1 for the ν3 band of methyl fluoride and 1040±40 cm2·mol−1 for the ν6 band of methyl iodide.
1H and 19F NMR Study of p-Chlorobenzylidyne Trifluoride Partially Oriented in a Nematic Phase
Authors: Sugino Yuuji , Takahashi Kensuke
Published: July 2006

The 1H and 19F NMR spectra of p-chlorobenzylidyne trifluoride dissolved in a nematic phase of EBBA have been analyzed, and the structure of the proton and fluorine skeleton has been determined. No presice information about the anisotropy of the indirect F-F coupling can be given.
Application of Gel Chromatography to the Determination of the Stability Constants of a Magnesium Complex with Diphosphate
Authors: Miyajima Tohru , Ohashi Shigeru
Published: July 2006

Hummel-Dreyer’s method was examined for its applicability to inorganic complexes, and a modified method was proposed. A sample solution containing magnesium and diphosphate was eluted with magnesium chloride solution on a gel column. The change of magnesium concentration in an effluent was measured with an atomic absorption detector. From the peak area of the eluted complex the stability constants (1g β1) at I=0.1 and 25 °C were evaluated to be 5.57 in tetramethylammonium chloride solution and 5.06 in sodium perchlorate solution. In the modified method the total magnesium concentration in a sample solution is made to be much higher than that in an eluent. This enables one to shorten the elution time.
Kinetics of the Oxidative Addition of Hydrogen to Chloro(acrylonitrile)bis(triphenylphosphine)rhodium(I) in Benzene
Authors: Ohtani Yoshimi , Yamagishi Akihiko , Fujimoto Masatoshi
Published: July 2006

The reaction between chloro(acrylonitrile)bis(triphenylphosphine)rhodium(I) and hydrogen was studied by the stopped-flow method under an anaerobic condition. A solution of RhCl(CH2=CHCN)(PPh3)2 was mixed with a benzene solution containing hydrogen under the condition of [Rh]<[H2]0<[CH2=CHCN]. A fast decrease in the absorbance was followed by a slow increase in the absorbance, until finally the absorbance returned to the initial value. It was proved that the faster reaction was the oxidative addition of hydrogen to RhCl(CH2=CHCN)(PPh3)2; RhCl(CH2=CHCN)(PPh3)2+H2\oversetk34\undersetk43\ightleftharpoonsRhClH2(CH2=CHCN)(PPh3)2. The slower reaction was the process in which hydrogen was consumed in the course of the hydrogenation of acrylonitrile and RhCl(CH2=CHCN)(PPh3)2 was reproduced. The values of the rate constants were evaluated to be k34≥7.8×103 mol−1 dm3 s−1 and k43≤53 s−1.
Annihilation of Positron and Positronium in Benzene Solutions of Lanthanoid Dipivaloylmethanates
Authors: Endo Kazutoyo , Furukawa Michiaki , Yamatera Hideo , Sano Hirotoshi
Published: July 2006

The lifetime of ortho-positronium(o-Ps) was measured in benzene solutions of several lanthanoid dipivaloylmethanates. None of the paramagnetic lanthanoid dipivaloylmethanates, Ln(dpm)3 (Ln=Eu, Gd, Tb, Dy, Ho, Er, and Yb), accelerated the o-Ps decay (τ2=3.2 ns). On the other hand, diamagnetic tetrakis(dipivaloylmethanato)cerium(IV), Ce(dpm)4, shortened the lifetime of o-Ps (τ2=1.9 ns for a 0.02 mol dm−3 solution in benzene). These results clearly indicate that the acceleration of the o-Ps decay by lanthanoid complexes occurs through the oxidation mechanism, not through the spin-conversion mechanism. This confirms the previous conclusion from experiments with 3d transition-metal β-diketonates that the oxidation of o-Ps is mainly responsible for the rapid o-Ps decay caused by the Fe(III) and Mn(III) complexes. Factors which influence the intensity and decay rate of o-Ps are discussed in connection with the experimental results.
Syntheses and Thermal Properties of Some Bivalent Transition Metal Complexes with 1,4-Diazabicyclo[2.2.2]octane
Authors: Yokobayashi Hiroko , Nagase Kenzo , Sone Kozo
Published: July 2006

New five-coordinate complexes [MCl3L(H+L)], where M=Mn(II), Fe(II), Co(II), and Ni(II) and L=1,4-diazabicyclo[2.2.2]octane, were prepared in anhydrous ethanol. On being heated in the solid state, they begin to lose the non-charged ligand (L) in the order Co(147 °C) <<Fe(184 °C)<Ni(190 °C)<Mn(196 °C) and are transformed into the tetrahedral complexes [MCl3(H+L)]. The thermal stability of the five-coordinate complexes depends markedly on the nature of M(II). The octahedral complex [NiCl4(H2O)2]H2L·H2O obtained from an aqueous solution shows a series of complicated color and structural changes on heating according to step-wise decomposition: [NiCl4(H2O)2]H2L·H2O (greenish yellow, octahedral)→[NiCl4]H2L(light blue, tetrahedral)→[NiCl3(H+L)](cobalt blue, tetrahedral)→[NiCl2L1⁄2](reddish brown, probably square-pyramidal)→NiCl2(yellow, octahedral).
Derivatographic Studies on Transition Metal Complexes. XX. Thermal Electron Transfer Reactions of Cobalt(III) Complexes Containing Phenylbiguanide in the Solid Phase
Authors: Ihara Yoshinori , Uehara Akira , Tsuchiya Ryokichi , Kyuno Eishin
Published: July 2006

The following six cobalt(III) complexes containing phenylbiguanide were prepared and the thermal reactions were followed both isothermally and non-isothermally (derivatographically) in the solid phase: trans-[Co(A)2(phbgH)2]X3·n2O, where A denotes volatile ligands such as NH3, CH3NH2 or C5H5N; phbgH denotes 1-phenylbiguanide, X chloride or bromide ion; and n is 2 or 3. From the electronic, IR and far-IR spectra and magnetic susceptibilities of these complexes before and after heating, the products obtained by evolving volatile ligands were found to be uniform bivalent cobalt complexes without rupture of the bonds of phbgH to cobalt in spite of the reduction of central cobalt(III) ion, except for the complexes containing ammonia. The reaction seems to be caused by the electron transfer from the coordinated phbgH to cobalt, not from the outer-sphere anions.
Reactions of Alkyl Diphenylphosphinates and Related Thio Esters with Some Nucleophiles. SN2 (S) Reaction and Wittig Type Rearrangement
Authors: Goda Koshiro , Okazaki Renji , Akiba Kin-ya , Inamoto Naoki
Published: July 2006

Reactions of alkyl diphenylphosphinates Ph2P(=X)YCHR1R2 (X, Y=O,S) with organolithiums and Grignard reagents afforded different types of products depending on the combination of X and Y. When Y=O, the reagents (R3M) mainly attacked the phosphorus atom to give Ph2P(=X)R3 and R1R2XCHO− irrespective of X, while, when X=Y=S, the reaction occurred exclusively at the ester sulfur atom, SN2(S), to give R3SCHR1R2 and [Ph2PS]−. When the X=O and Y=S, a Wittig type rearrangement of a carbanion [Ph2P(=O)SCR1R2]− was observed along with attacks on the phosphorus (major) and the sulfur (minor) atoms. Reactions with some other nucleophiles (hydride, amide and alkoxide ions) are also described.
Aromatic Nucleophilic Substitution. X. Confirmation of the Anionic σ Complex in the Base-catalyzed Smiles Rearrangement of 2-(Acetylamino)ethyl 2,4-Dinitrophenyl Ether in Dimethyl Sulfoxide
Authors: Okada Keiji , Matsui Kohji , Sekiguchi Shizen
Published: July 2006

2,4-Dinitrofluorobenzene reacts with 2-(acetylamino)ethanol in dioxane in the presence of sodium to give 2-(acetylamino)ethanol 2,4-dinitrophenyl ether (7), N-(2-acetoxyethyl)-2,4-dinitroaniline (8), which is considered to be a Smiles rearranged product of 7, and N-(2-hydroxyethyl)-2,4-dinitroaniline (9), a hydrolysis product of 8. Furthermore, 7 undergoes a Smiles rearrangement in DMSO in the presence of NaOCH3 or KOC(CH3)3, giving 8 and 9. Spiro Janovsky complex was spectrpmetrically confirmed to exist during the course of rearrangement.
Kinetic and Stereochemical Studies of the Reaction of Trialkyl(alkylthio and arylthio)stannanes with Haloalkanes
Authors: Kozuka Seizi , Ohya Sadamu
Published: July 2006

A kinetic study has been conducted on the reaction of arylthio(trimethyl)stannane with haloalkanes giving halotrimethylstannane and alkyl aryl sulfide. The reaction has been found to obey second order kinetics. Substituent effects of the arylthio group, solvent effects, relative reactivities of the leaving halogens and steric effects of the haloalkanes have been investigated. Optically active (+)-1-methylheptyl bromide gives an inverted product i.e., (−)-methyl 1-methylheptyl sulfide by the reaction with trimethyl(methylthio)stannane. A mechanism involving bimolecular nucleophilic attack of the sulfur atom on the haloalkane has been confirmed for the reaction.
A Highly Stereoselective Reduction of Substituted Cyclohexanones Using Triisobutylaluminum–Amine Complexes
Authors: Suzuki Toshimitsu , Itoh Maki , Ogawa Shigeyuki , Takegami Yoshinobu
Published: July 2006

The stereochemistry of the reduction of substituted cyclohexanones with a triisobutylaluminum(TIBA)–amine complex has been investigated, and the origin of the stereoselectivity has been discussed. Although a reduction of 4-t-butylcyclohexanone with free TIBA at 60 °C gave 83% trans alcohol, with a high stereoselectivity, 91–98% trans alcohol was obtained in this study. In order to discuss the reactivity of the reagent, the mode of the complexing of an amine to TIBA was investigated by infrared and NMR spectroscopy.
General Synthesis of Phosphonates from Heteroniaanthracene Cations and Their Use in Wittig-Horner Reaction
Authors: Ishikawa Kiyofumi , Akiba Kin-ya , Inamoto Naoki
Published: July 2006

Heteroaromatic cations such as 9-heteroniaanthracene (acridinium, xanthylium, and thioxanthylium) and 1-thionianaphthalene (thiochromenylium) ions reacted with trimethyl phosphite in the presence of sodium iodide in acetonitrile at room temperature to give the corresponding phosphonates (2 and 4) respectively in 76–92% yields. The phosphonates were deprotonated with butyllithium in THF at −78 °C, and the resulting carbanions reacted with p-tolualdehyde, cinnamaldehyde, and 4,4′-dichlorobenzophenone to afford the corresponding exomethylene containing heterocyclic compounds, respectively, in 52–96% yields. However, the phosphonate carbanions derived from 2 did not react with cycloalkanones and butanal.
Preparation of D:B-Friedoolean-5(10)-en-1-one and Related Compounds. A Comment on the Structure of “Glut-5(10)-en-1-one” from Euphorbia Nerifolia
Authors: Akiyama Eri , Moriyama Yoshihiko , Murae Tatsushi , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

In order to examine the structure, “glut-5(10)-en-1-one”, proposed for a new triterpene from Euphorbia nerifolia, this ketone (≡ D : B-friedoolean-5(10)en-1-one) was prepared. Oxidation of D : B-friedoolean-5(10)-ene with chromium trioxide-pyridine complex gave the allylic oxidation products, D : B-friedoolean-5(10)-en-1-one, D : B-friedoolean-5(10)-en-6-one, and D : B-friedoolean-5(10)-ene-1,6-dione. The spectral data and physical constants of the synthetic ketone (D : B-friedoolean-5(10)-en-1-one) were not identical with those of the new triterpene; this requires revision of the structure of this natural triterpene. Oxidation of D : B-friedoolean-5(10)-en-3-one enol acetate under the same conditions to give D : B-friedooleane-1,5(10)-dien-3-one is also described.
Peptide Syntheses with Proteinases. Fragment Condensation of ZLeuGlnGlyOH or ZGlnGlyOH with HLeuValNH2 Using Metalloproteinases
Authors: Isowa Yoshikazu , Ichikawa Tetsuya , Ohmori Muneki
Published: July 2006

The crude preparations of microbial metalloproteinase from Bacillus subtilis var. amyloliquefaciens (Prolisin) catalyzed the condensation of ZLeuGlnGlyOH or ZGlnGlyOH with HLeuValNH2 in the presence of the serineproteinase inhibitor from potatoes to give the corresponding Z-penta or tetra-peptide amide in good yields in an aqueous buffer solution. Two other metalloproteinases, from Bacillus thermoproteoliticus (Thermolysin or Thermoase) and Streptomyces caespitosus (Tacynase N), also catalyzed this reaction; however, they gave poorer results than Prolisin. The yields of the coupling products were affected most by the concentration of the substrates, among the several factors investigated. Addition of a small amount of an organic solvent sometimes promoted the yield for this method.
Studies in Isodielectric Media. The Standard Potentials of Ag–AgCl and Ag-AgBr Electrodes in 1,2-Ethanediol-2,2′-Oxydiethanol Mixtures at 25 °C
Authors: Sivaprasad P , Kalidas C
Published: July 2006

Standard potentials of Ag-AgCl and Ag-AgBr electrodes in various compositions of 1,2-ethanediol-2,2′-oxydiethanol (ethylene glycol-diethylene glycol) mixtures at 25 °C are reported. The free energies of transfer of the hydrogen halides from ethylene glycol to the mixtures were evaluated on mole fraction scale. The transfer free energies of H+ and the halide ions were determined employing the ferrocene reference method. The results suggest that the basicity of the mixtures increases with the addition of diethylene glycol and that it is more basic than ethylene glycol.
The Preparation of 2,2′-Bipyridinedicarbonato and Dicarbonato-1,10-phenanthroline Complexes of Cobalt(III)
Authors: Ida Yayoi , Imai Kiyoyuki , Shibata Muraji
Published: July 2006

Two new dicarbonato complexes, K[Co(CO3)2(bpy)]·2H2O and K[Co(CO3)2(phen)]·H2O, have been prepared by the method starting from the [Co(Co3)3]3− complex and resolved by means of diastereoisomer formation.
Cyclopentadienyl- and Pentamethylcyclopentadienylbis(isocyanide)cobalt(I)
Authors: Yamamoto Yasuhiro , Mise Takaya , Yamazaki Hiroshi
Published: July 2006

Compounds, η-C5H5Co(RNC)2 and η-Me5C5Co(RNC)2 were prepared from Co2(RNC)8 and C5R5H (R=H, CH3), and from η-C5H5Co(CO)2 and isocyanide.
Synthesis of 5-(Substituted methyl)-6,8-dimethyl-4-chromanones
Authors: Ninagawa Akira , Matsuda Haruo
Published: July 2006

5-(Substituted methyl)-6,8-dimethyl-4-chromanones were synthesized from the reactions of 5-hydroxymethyl-6,8-dimethyl-4-chromanone with nucleophilic reagents in acid media, and the reactions of its 5-halomethyl derivatives with ethoxide or phenoxide nucleophiles.