bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric Epoxidation of Simple Olefins by Chiral Bitetralin-Linked “Twin-Coronet” Porphyrin Catalysts
Authors: Naruta Yoshinori , Ishihara Nobuo , Tani Fumito , Maruyama Kazuhiro
Published: August 2006

Catalytic and asymmetric epoxidation of styrenes and related aryl substituted olefins with the iron complexes of chiral bitetralin (Bitet)–linked “twin–coronet” porphyrins was performed with iodosylbenzene as an oxidant. Among two topological isomers of the catalyst, the eclipsed one (5b) showed higher enantioselectivity than the staggered (6b). With 5b, the resulting epoxides, except for the olefins bearing an electron–donating substituent, were obtained in good to excellent enantioselectivity (54—96% ee), especially for the styrenes with electron–withdrawing substituent(s). Being different from other porphyrin–based chiral catalysts, the catalyst 5b is robust enough under the applied oxidation conditions to exhibit chiral epoxidation with the same ee and the same rate as those of the initial period of the reaction even after about 500 turnovers. The Bitet catalyst is superior in the epoxide enantioselectivity than the corresponding chiral binaphthalene (Binap)–linked catalyst (3b). In the reactions with the catalysts 3b and 5b, good correlation in epoxide ees was observed. Increase of the epoxide ee in the reaction with the Bitet catalyst was elucidated by the shape and size of the reaction cavities of the Bitet were tighter than those of the latter. The observed ees of the substituted styrene oxides showed good correlation with Σσ+ values of their substituent(s). In the reaction with the electron–deficient olefins, π–π* interaction between the HOMO of the electron–rich Bitet auxiliary ring and the LUMO of the electron–deficient aryl ring of the substrate are pointed out as the key for the realization of high ees. Some nitrostyrenes, however, gave rather lower ees in spite of rather higher degree of their electron deficiency. This deviation was elucidated by the mismatching of their frontier orbitals.
Photoinduced Alkoxylation of 2-Vinylpyridinium Ion
Authors: Ishida Akito , Uesugi Tatsumi , Takamuku Setsuo
Published: August 2006

Photoirradiation of 2-vinylpyridine in acidic methanol afforded methyl 2-(2-pyridyl)ethyl ether in a high yield. Reactions in acidic ethanol and 2-propanol also provided the corresponding alkoxyl derivatives along with a considerable amount of 2-ethylpyridine. It was suggested that photoinduced intramolecular charge-shift from the pyridinium ion moiety into the vinyl group initiates the regioselective nucleophilic addition of alcohol.
Correlation of Reaction Rates with a Substituent Constant Scale Derived from Calculated Electron Densities for a Computer Control Algorithm
Authors: Cork David G , Hayashi Nobuyoshi
Published: August 2006

A new σ substituent scale based on electron density calculations by the AM1 quantum mechanical model has been established and used to correlate rates of O-methylation of substituted phenols, as part of a chemical artificial intelligence to control a fully automated apparatus for [11C]methyl iodide labeling.
Electroosmotic Transport of Urea and d-Glucose Solutions across Progesterone Plug Membrane
Authors: Srivastava Mahendra Lal , Ram Bali
Published: August 2006

Studies on hydrodynamic and electroosmotic permeation of water, aqueous solutions of d-glucose and urea in the concentration range 10−4 to 10−3 mol dm−3 across progesterone plug membrane have been carried out to characterize the electrical nature of interface. Phenomenological coefficients have been evaluated from the linear and nonlinear equations obtained. Membrane properties viz., pore radius and zeta potentials have been determined using these coefficients. The nonlinear variation of electroosmotic flow in case of aqueous solutions of urea has been explained on the basis of electrical double layer theory and the structural modifications that are likely to occur at membrane–solution interface because of solute–solvent, solvent–solvent, and membrane–permeant interactions.
Solution Properties of Polyvinylpyridine in Acidic Solvent. I. Solution Properties of Poly(2-vinylpyridine) in Aqueous Solution of Sulfuric Acid
Authors: Yoshida Masafumi , Sakamoto Noriyuki , Ikemi Kimiyoshi , Arichi Shizuo
Published: August 2006

Measurements of the light scattering and viscosity of poly(2-vinylpyridine) (P2VP) in an aqueous (aq) solution of H2SO4 at 25 °C were carried out. Although from Stockmayer–Fixman’s theory the characteristic ratio (C∞) was found to be almost constant over the range from 0.1 M to 5.1 M H2SO4, the long-range interaction parameter was found to change through the minimum. The difference among the interaction parameters of P2VP and those of poly(4-vinylpyridine) (P4VP) reported before is discussed. Both the second virial coefficient (A2) and the mean-square radius of gyration () of the atactic P2VP sample based on a light-scattering measurement decreased at first with increasing concentration of H2SO4, and then increased through the minimum. The variation of A2 and  from light scattering with the concentration of H2SO4 has the same tendency as that of the intrinsic viscosity ([η]).
Physical Properties of Binary Mixtures of 3-Propylsydnone–Tetrahydrofuran and 1,2-Dimethoxyethane
Authors: Sasaki Yukio , Miyagawa Ken-ichi , Wataru Nobuyuki , Kaido Hideki
Published: August 2006

The physical properties of binary mixtures of 3-propylsydnone (3-PSD)–tetrahydrofuran (THF) and 1,2-dimethoxyethane (DME) at various temperatures were investigated in terms of the dielectric constant (ε), refractive index (nD), density (ρ), and viscosity (η) measurements. The dielectric constants of these binary mixtures gradually decrease with increasing THF and DME mole fractions (XTHF and XDME). The dielectric constant data can be described by a cubic equation of the THF and DME mole fractions. The nD of these binary mixtures decreases linearly with increasing temperature. A linear relationship exists between the density and the temperature at each XTHF and XDME. The η of these binary mixtures rapidly decrease with increasing XTHF and XDME at low temperature. The excess viscosity (ηE) of the mixtures is negative over the entire THF and DME mole fractions, and has a maximum value at 0.4 XTHF and XDME. The negative value of ηE may be taken as the formation of weakly associated compounds. It was found from the 1H and 17O NMR spectra that the interaction in a 3-PSD–THF mixture occurs highly between the hydrogen of the 4-position in the sydnone ring and the oxygen of the THF molecule. From the ηE and NMR spectra it seems that one of the associated compounds due to weak hydrogen bonding in these binary mixtures is formed at the 0.4 THF and DME mole fractions. The interactions in these binary mixtures were investigated on the basis of the activation parameters by using the Eyring rate equation. The activation enthalpy (ΔHη*) gradually increases with increasing viscosity of the mixtures. It is considered that the mechanism of viscous flow for these binary mixtures is a thermally activated single process. The activation entropy (ΔSη*) gradually changes from positive to negative with increasing XTHF and XDME. It seems that the change of sign in ΔSη* near to 0.4 THF and DME mole fractions depends on the formation of weakly associated compounds at that mole fraction. The activation Gibbs energy (ΔGη*) with a positive ΔSη* value gradually decreases with increasing temperature. On the contrary, the ΔGη* with a negative ΔSη* value gradually increases with increasing temperature. This means that the change in ΔSη* greatly contributes to that of ΔGη*.
Binding of Dibucaine to Phospholipid Mixed Vesicles
Authors: Fukushima Kohsuke , Someya Masayuki , Shimozawa Ryosuke
Published: August 2006

Binding isotherms of a local anesthetic, dibucaine, to phospholipid vesicles were measured using a dialysis method. Two types of phospholipids, dilauroylphosphatidic acid (DLPA) and dilauroylphosphatidylcholine (DLPC), were used to prepare vesicles. The binding isotherms for pure DLPA and DLPC vesicles and their mixtures were analyzed with the Hill equation. The binding parameters obtained for pure phospholipid vesicles reproduce the binding isotherms for the mixed vesicles by taking account of the mixing ratio; this indicates the presence of independent binding sites, corresponding to the DLPA and DLPC molecule, in the mixed vesicle.
The Micellar Properties of α,ω-Alkanediammonium Bis(dodecyl sulfate) in Aqueous Solutions
Authors: Satake Iwao , Fukunaga Tomoko , Maeda Tamaki , Soeda Yuko , Hayakawa Katumitu
Published: August 2006

The micellar properties of α,ω-alkanediammonium bis(dodecyl sulfate) with hydrocarbon chain length (n) from 3 to 6 were studied by conductivity, surfactant ion activity, and fluorescence quenching measurements. The critical micelle concentration (CMC) decreases gradually with increasing n in such a way that ln CMC vs. n plot gives a straight line above n = 3. The binding degree of counterion head group to the micelle remains virtually constant of 0.95 regardless of n studied. The estimated value of −0.36 kT for the transfer free energy per methylene group of counterion from aqueous to micellar environments suggests that the hydrocarbon part of the counterion participates in the weak hydrophobic interaction with micellar core. Although the micelle aggregation number is always larger than those of bivalent metal dodecyl sulfates, it tends to decrease as n increases.
Multi-Reference CI Calculation of Potential Energy Curves for cis–trans Isomerization of Stilbene Cation Radical
Authors: Oshiyama Tomohiro , Takahashi Ohgi , Morihashi Kenji , Kikuchi Osamu , Tokumaru Katsumi
Published: August 2006

Ab initio and AM1 multi-reference SCI calculations have been applied to the stilbene cation radical and the potential energy curves for the lower doublet states were obtained as a function of the twist angle about the central C–C bond to elucidate the photochemical cis–trans isomerization process. The shape of the calculated potential energy curves has suggested that the cis→trans one-way isomerization proceeds very efficiently from an upper excited state of the cis-stilbene cation radical.
CIDEP Study of Radicals Produced Photochemically in the Organic Solution of 9-Acridone and Phenols
Authors: Niizuma Shigeya , Kawata Hiroki
Published: August 2006

The photoreaction of the solution systems of 9-acridone (or N-methyl-9-acridone) and phenols was investigated by optical spectroscopy, ESR, and time-resolved CIDEP techniques. CIDEP signals of acridone semiquinone and phenoxyl radicals were detected together and the hyperfine coupling constants of acridone semiquinone were determined for the first time by simulation method. It was also clarified that radical pair mechanism (RPM) with triplet precursor and triplet mechanism (TM) were the main spin polarization mechanisms in these systems. The results indicate that the excited triplet state of acridone abstracts a hydrogen of phenols. Temperature, phenol concentration, light intensity and time dependence of the phenoxyl CIDEP signal intensity and/or pattern supported the conclusion.
Behavior of Surfactants in the Suspension of Coal Components
Authors: Ogura Tsugitoshi , Tanoura Masazumi , Hiraki Akio
Published: August 2006

The roles and behaviors of an anionic surfactant, such as naphthalenesulfonate-formaldehyde condensate (NSF) and poly(styrenesulfonate) (PSS) in the high-loaded suspensions of the Celejon coal with low mineral content (1.2%), carbon black, kaolinite, and montmorillonite were studied. It was found that it is necessary to prepare a slurry of low-viscosity Celejon coal, carbon black and kaolinite in such a way that the surfactant is present as saturatedly adsorbed on the particles as well as being free in water. In the presence of a surfactant, high-loaded suspensions exhibited non-Newtonian fluidity without yield values in their shear-rate and shear stress relation. In contrast, neither NSF nor PSS showed any adsorption on the bentonite particles. Its suspension exhibited a non-Newtonian fluidity with the yield value, even if its concentration was low. The roles of the bentonite were confirmed by adding bentonite to the CWM of Celejon. The CWM of Taiheiyo coal which carried 4.81% montmorillonite suffered a limited coal concentration due to because of a large yield value. Sodium polycarbonate was found to be effective to reduce the yield value, allowing a high coal concentration in CWM.
O2 and CO Binding Behavior of Double-Sided Porphyrinatoiron(II) Complexes Modified by Amide Residues
Authors: Komatsu Teruyuki , Kumamoto Shin-ichi , Nishide Hiroyuki , Tsuchida Eishun
Published: August 2006

New double-sided porphyrinatoiron(II) complexes having a polar cavity which includes an amide moiety (5,10,15-tris[2,6-bis(3,3-dimethylbutyryloxy)phenyl]-20-[2-[N-acetylvalyloxy]-6-(3,3-dimethylbutyryloxy)phenyl]porphinatoiron(II) (1b) and 5,10,15-tris[2,6-bis(3,3-dimethylbutyryloxy)phenyl]-20-[2-[3,5-bis(acetamido)benzoyloxy]-6-(3,3-dimethylbutyryloxy)phenyl]porphinatoiron(II) (2b)) were synthesized. 1H NMR spectroscopy indicated that the amide residues are located on the porphyrin ring plane. The O2 and CO binding affinities of 1b and 2b were higher than those of 5,10,15,20-tetrakis[2,6-bis(3,3-dimethylbutyryloxy)phenyl]porphinatoiron(II) (4b), in response to the local polarity in the cavity. The polar amide residue resulted in a decreased O2 dissociation rate. Thermodynamic parameters for the gaseous ligand bindings to the 2b complex were also determined.
Cobalt(III) Complexes with Quadridentate Ligands. XII. Crystal Structure of cis-α-Salicylato(triethylenetetramine)cobalt(III) Chloride Pentahydrate
Authors: Sekizaki Haruo , Toyota Eiko , Yamamoto Yoshihisa
Published: August 2006

The structure of the cis-α-salicylato(triethylenetetramine)cobalt(III) ion was confirmed by an X-ray crystallographic analysis. The conformation of the triethylenetetramine part of this complex was slightly different from the cis-α-glycinato(triethylenetetramine)cobalt(III) ion. A comparison of the stability of the this cis-α-salicylato complex with that of the cis-α-glycinato complex on the cation-exchange resin and in water, respectively, are described. The signals of the 1H NMR and 13C NMR spectra were assigned based on the crystal structure.
Preparation and Characterization of Ethylenediaminetrihalogenonitrosylruthenium(III) Complexes
Authors: Tomizawa Hiroshi , Harada Kazumasa , Miki Eiichi , Mizumachi Kunihiko , Ishimori Tatsujiro , Urushiyama Akio , Nakahara Masayoshi
Published: August 2006

A mixture of mer- and fac-[RuCl3(en)NO], and mer-[RuX3(en)NO] (X = Br or I) were prepared from the corresponding [RuX5NO]2− (X = Cl, Br, or I) or hydrous RuX3·NO (X = Cl or Br) and en·2HX (en = ethylenediamine; X = Cl or Br). The crystal and molecular structures of mer-[RuX3(en)NO] (X = Cl, Br, or I) were determined by X-ray diffraction. The crystals were isomorphous; triclinic, with space group P1. The final R values were 0.0411 for [RuCl3(en)NO], 0.0271 for [RuBr3(en)NO], and 0.0535 for [RuI3(en)NO]. In these complexes, the three halogeno atoms were in the meridional arrangement and in a position cis to the NO. In all of the mer-complexes, the trans-strengthening effect which is expected to be caused by the NO was not observed for the Ru–N(en) bond. The synthesized complexes were also characterized by IR and NMR spectra.
Dual Cation-Selective Membrane Tube Electrodialysis/Ion Chromatography for Halide Ions in Strongly Basic Solutions and Its Application to the Analysis of Rock Samples
Authors: Okamoto Yasuaki , Hayashi Kiyoshi , Kawahara Yukihiro , Kumamaru Takahiro
Published: August 2006

Electrodialysis pretreatment system was combined with a new dual cation-selective membrane tubes and was employed to reduce the basicity of the strongly basic sample solution prior to the ion chromatographic determination of halide ions by using a sodium salicylate solution as eluent. By using this system, large amount of cations such as sodium and potassium ions could also be removed from the sample solution through the membrane. The detection limits were 9.7, 5.4, 22.7, and 163 ng cm−3 and relative standard deviations at 0.5 μg cm−3 were 1.7, 1.2, 2.4, and 14% for fluoride, chloride, bromide, and iodide ions, respectively. Analytical results are given for rock samples fused with sodium hydroxide as a flux and afterward dissolved in water which shows strong basicity.
Studies on the Vilsmeier-Haack Reaction. Part XI. Novel Heterocyclo-Substituted Thioquinoxalinone Dyes
Authors: Awad Ibrahim M A
Published: August 2006

Novel azo sulfa drugs of 3-methyl-1-[4-(substituted sulfamoyl)phenylazo]-2(1H)-quinoxalinethiones were synthesized and found to undergo diformylation reaction with Vilsmeier reagent giving the 3-(3-aminoacrylaldehyde-substituted)-1-(4-sulfamoylphenylazo)-2(1H)-quinoxalinethione dyes 4—6. Reaction of 4, 5, and/or 6 with proper reagents afforded the corresponding morpholinyl, piperidinyl, 4-piperazinyl-1H-pyrazol-4-yl, 1-phenyl-1H-pyrazol-4-yl, 4-isoxazolyl, and 5-amino-1H-pyrazol-4-yl substituted 2(1H)-quinoxalinethione derivatives at the 3-position of the quinoxaline moiety. The structures of these novel compounds were confirmed by elemental analysis, IR and 1H NMR spectroscopy and screened in vitro for antibacterial (Gram-positive and Gram-negative bacteria) and antifungal activites.
Preparation and Characterization of 11-Molybdoarsenite(III) Complex
Authors: Maeda Kohji , Himeno Sadayuki , Saito Atsuyoshi , Hori Toshitaka
Published: August 2006

A green 11-molybdoarsenite(III) complex, which was formed in an Mo(VI)–AsO33−–HCl–CH3CN system at room temperature, was isolated as the tetrabutylammonium (n-Bu4N+) salt, being characterized by its voltammetric behavior and its IR and UV-visible spectra. The heteropolyanion undergoes two-step one-electron reductions in CH3CN and three-step two-electron reductions in acidified CH3CN. The electrochemical reduction produces mixed-valence blue species at the glassy carbon (GC) electrode. The formation conditions and chemical properties were compared with those of 12-molybdoarsenate(V) with the Keggin structure. The presence of water-miscible organic solvents like CH3CN and CH3COCH3 is absolutely necessary for the formation of the green heteropolyanion.
Reaction of Hydrazinobenzoquinolines with 1,3-Diketones: A Structural Reinvestigation
Authors: Singh Shiv Pratap , Kapoor Jitander Kumar , Kumar Devinder
Published: August 2006

Reaction of several hydrazinobenzoquinolines with 1,3-diketones affords pyrazolylbenzoquinolines rather than the reported benzodiazepinoquinolines. The structural assignment is based upon NMR (1H and 13C) spectral data and an unambiguous synthesis.
Soluble Itaconic Acid–Ethylene Glycol Polyesters
Authors: Retuert J , Pedram M Yazdani- , Martínez F , Jeria M
Published: August 2006

A method of obtaining soluble itaconic acid (IA)–ethylene glycol (EG) unsaturated polyesters was developed. The reaction between IA and EG was conducted under moderate vacuum (50—60 mmHg) at 120 °C and stopped by nearly 85% conversion to avoid crosslinking. No isomerization of itaconate to citraconate and/or mesaconate was observed. The residual double bond contained in the polyester resin showed to be highly reactive and promoted gelification after few days. Therefore copolymerization reactions of the resin with a variety of vinyl monomers proceed without radical initiator. The synthetic method was successfully applied to reactions of IA with other glycols.
Synthesis of 2,3-Dideoxy-2-[(3R)-3-hydroxytetradecanoylamino]-3-C-[(3R)-(3-hydroxytetradecanoyloxy)methyl]-4-O-phosphono-d-mannopyranose
Authors: Shiozaki Masao , Arai Masami , Hiraoka Tetsuo , Nishijima Masahiro , Akamatsu Yuzuru
Published: August 2006

2,3-Dideoxy-2-[(3R)-3-hydroxytetradecanoylamino]-3-C-[(3R)-(3-hydroxytetradecanoyloxy)methyl]-4-O-phosphono-d-mannopyranose was synthesized from (1R,2S,4S,5S)-6-(2,4-dimethoxybenzyl)-4-hydroxy-2-[(1R)-1,2-isopropyridenedioxyethyl]-3-oxa-6-azabicyclo[3.2.0]heptan-7-one.
Formation and Reactions of Novel Heterocycles: 1,3,4-Oxadithiolane, 1,3,4-Oxadiselenolane, 1,3-Oxathietane, and 1,3-Oxaselenetane Derivatives
Authors: Ding Meng-Xin , Ishii Akihiko , Nakayawa Juzo , Hoshino Masamatsu
Published: August 2006

The reactions of 2,2,4,4-tetramethyl-1,5-diphenyl-1,5-pentanedione monohydrazone with S2Cl2 and Se2Cl2 gave 2,2,4,4-tetramethyl-1,5-diphenyl-8-oxa-6,7-dithiabicyclo[3.2.1]octane (9) and 2,2,4,4-tetramethyl-1,5-diphenyl-8-oxa-6,7-diselenabicyclo[3.2.1]octane (10), respectively. Dechalcogenation of 9 or 10 with triphenylphosphine in boiling toluene yielded an equilibrium mixture of 2,2,4,4-tetramethyl-1,5-diphenyl-6-oxa-7-thiabicyclo[3.1.1]heptane (11) and 2,2,4,4-tetramethyl-1,5-diphenyl-5-thioxo-1-pentanone (13) or 2,2,4,4-tetramethyl-1,5-diphenyl-6-oxa-7-selenabicyclo[3.1.1]heptane (12), respectively. On the other hand, the reaction of 10 with hexamethylphosphorous triamide [P(NMe2)3] in boiling toluene gave 12, 3-methyl-3-(2,2-dimethyl-3-oxo-3-phenylpropyl)-2-phenylselenetanes (18), 5-benzoyl-3,3,5-trimethy1-2-phenylselenanes (19), 6,6,8,8-tetramethyl-9-phenyl-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one (20), and 3,3,5,5-tetramethyl-1,2-diphenylcyclopentene (21), while that of 9 afforded 11, 13, 3-(2-benzoyl-2-methylpropyl)-3-methyl-2-phenylthietanes, 20, and 21. The reaction of 12 with P(NMe2)3 also gave 18, 19, 20, and 21. A single-electron transfer mechanism seems to be operative in the reaction of 9 or 10 with P(NMe2)3. Compounds 11 and 13 are in equilibrium with each other at room temperature, while a ring-opening of 12 to 2,2,4,4-tetramethyl-1,5-diphenyl-5-selenoxo-1-pentanone is observed on heating by the UV-vis and 1H NMR spectra.
Heterocyclic Synthesis with Nitriles: Synthesis of Some New Mercapto-Substituted Heterocycles from Alkylidenemalononitrile
Authors: Abdelrazek Fathy Mohamed , Salah Abdellatif Mohamed
Published: August 2006

α-(Thiocyanatomethyl)benzylidenemalononitrile undergoes azo coupling with diazotized aromatic amines (ArNH2) to afford azo derivatives. The azo derivatives (Ar = Ph, 4-MeC6H4, 4-ClC6H4, 4-MeOC6H4) were readily cyclized on reflux in aqueous NaOH to 3(2H)-pyridazinimine derivatives. These latter compounds were transformed into the corresponding pyrrole derivatives on reflux in glacial acetic acid with Zn dust presumably via reductive cleavage of the N–N bond followed by recyclization with loss of ammonia. Under similar conditions the azo derivative (Ar = 2-NCC6H4) was cyclized into 6H-pyridazino[3,2-a]quinazolin-6-imine derivative which was easily transformed into the 6H-pyridazino[3,2-a]quinazolin-6-one on reflux in ethanolic HCl. This last compound was also obtained from the azo derivatives (Ar = 2-HOOCC6H4 and 2-MeOOCC6H4) by reflux in aq NaOH. The starting benzylidenemalononitrile reacts also with arylmethyleneamalononitrile or ethyl arylmethylenecyanoacetate (aryl = Ph, furyl, or thienyl) to afford substituted benzonitrile derivatives.
Number and Structure of Solvolysis Intermediates. Part 2. A Novel Example of the Common Ion Rate Depression Arising at the Stage of the Second Ion Pair Intermediate in the SN1 Solvolysis
Authors: Kinoshita Tomomi , Shibayama Koichi , Itoh Masaaki , Takeuchi Ken’ichi
Published: August 2006

The solvolysis of 2,2-dimethyl-1-(p-methoxyphenyl)propyl p-nitrobenzoate in phenol provides a novel example of the common ion salt effect (rate depression) which arises at the stage of the second ion pair intermediate (Int-2; the rear-side shielded ion pair intermediate), not the dissociated (free) carbocation intermediate as generally supposed so far. This example demonstrates that “the common ion rate depression” could not give evidence for the intermediacy of the dissociated carbocation intermediate in the SN1 solvolysis, but an indicator for the stability of solvolysis intermediates including the ion pair intermediate.
NMR Spectra of Organogermanium Compounds. Part XII. 73Ge and 13C NMR Spectra and Molecular Mechanics Calculations of 3-Germabicyclo[3.1.0]hexanes and Related Compounds
Authors: Takeuchi Yoshito , Zicmane Ieva , Manuel Georges , Boukherroub Rabah
Published: August 2006

73Ge and 13C NMR spectra of several 3-germabicyclo[3.1.0]hexanes (GBCH) were determined. The results are consistent with the structure as predicted by molecular mechanics calculations. Thus, GBCH prefer the boat form as bicyclo[3.1.0]hexanes (BCH) do. GBCH finally assumes the chair form by excessive substitution.
Stereoselective Synthesis of Trans Isomers of a Volatile Compound Isolated from the Elm Bark Beetle “Pteleobius vittatus” via Stereospecific Cyclodehydration Route
Authors: Chikashita Hidenori , Hirao Kiyoharu , Itoh Kazuyoshi
Published: August 2006

The stereoselective asymmetric synthesis of two trans isomers of the title natural product, (3R,6R)- and (3S,6S)-tetrahydro-2,2,6-trimethyl-2H-pyran-3-ol, was achieved by starting with easily obtainable ethyl (S)-3-hydroxybutanoate, via the stereospecific asymmetric construction of substituted tetrahydropyran skeletons by the one-step cyclodehydration process of dithioacetal-functionalized chiral 1,5-diols with PPh3 and diethyl azodicarboxylate in THF at room temperature.
Pyrolysis of (2-Phenylethyl)phenylsulfonium Ylides
Authors: Yoshimura Toshiaki , Motoyama Atsushi , Morishige Akiko , Tsukurimichi Eiichi , Shimasaki Choichiro , Hasegawa Kiyoshi
Published: August 2006

In order to obtain information concerning the reaction mechanism of the pyrolysis of sulfonium ylides bearing a substituted phenyl group on the 2-position in the S-ethyl group of ethylphenylsulfonium ylide, (2-phenylethyl)phenylsulfonium bis(methoxycarbonyl)methylide (1) and dicyanomethylide (2) were subjected to pyrolysis in benzene. The reaction rates of 1 and 2 at 140 °C were 6.0- and 3.2-times faster than those of ethylphenylsulfonium bis(methoxycarbonyl)methylide and dicyanomethylide, respectively. The activation parameters for 1 were ΔH‡ = 125 kJ mol−1 and ΔS‡ = −3.8 J K−1 mol−1, while those for 2 were ΔH‡ = 124 kJ mol−1 and ΔS‡ = −2.5 J K−1 mol−1. Substituent effects on the β-phenyl groups in 1 and 2 afforded positive Hammett ρ-values: ρ = 0.49 (γ = 0.997) and ρ = 0.26 (γ = 0.993), respectively.

From the obtained results, it was suggested that the pyrolysis proceeds through essentially a concerted intramolecular cis-elimination inclined toward a slightly carbanion-like type from an E1-like type by introducing a phenyl substituent at the 2-position of the ethyl group in the ethylphenylsulfonium ylide.
Synthesis of Optically Active Lactones and 3-Cyclopentenone from Optically Active 3,3-Dialkyl-4-thianones
Authors: Matsuyama Haruo , Fujii Sana , Nakamura Yoshihiro , Kikuchi Koichi , Ikemoto Isao , Kamigata Nobumasa
Published: August 2006

The Optically active 3,3-dialkyl-4-thianones 3 and 4 were prepared in moderate yields with about 90% enantiomeric purity using an asymmetric process involving a Michael-type alkylation of chiral 3-alkyl-4-thianimines with methyl vinyl ketone or methyl acrylate. The diketones 3 were then transformed into new heterocycles 5 by base-induced cyclization. 3-Methyl- and 3-allyl-3-(2-methoxycarbonylethyl)-4-thianone ((+)-4a and (+)-4b) were converted into the bicyclic lactones (−)-6 and (−)-7, respectively. The stereochemistry of the sulfone (+)-8 derived from the lactone (−)-6a was determined by a X-ray crystal structure analysis. Desulfurization of the lactone (−)-6b using nickel boride afforded the corresponding lactone (+)-9. A synthesis of optically active 2-alkyl-2-methyl-3-cyclopentenone (S)-(+)-15 via the Ramberg–Bäcklund reaction from the keto ester (R)-(+)-4a was also accomplished.
Syntheses and Reactions of Metal Organics. XVIII. Syntheses of (1H,1H,2H,2H-Polyfluoroalkyl)trimethoxysilanes and Surface Modification of Glass Plate
Authors: Yoshino Norio , Yamamoto Yasushi , Hamano Katsumi , Kawase Tokuzo
Published: August 2006

Four silane coupling agents, (1H,1H,2H,2H-polyfluoroalkyl)trimethoxysilanes ((1H,1H,2H,2H-henicosafluorododecyl)trimethoxysilane, C10F21C2H4Si(OCH3)3, (1H,1H,2H,2H-heptadecafluorodecyl)trimethoxysilane, C8F17C2H4Si(OCH3)3, (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane, C6F13C2H4Si(OCH3)3, and (1H,1H,2H,2H-nonafluorohexyl)trimethoxysilane, C4F9C2H4Si(OCH3)3), were prepared by the hydrosilylation of trichlorosilane with the corresponding 1H,1H,2H-polyfluoro-1-alkene in the presence of hydrogen hexachloroplatinate(IV), followed by reaction with sodium methoxide. The surface modification of glass plate was attempted using these products. From measurements of the contact angles θ (°) of water and oleic acid against a modified glass plate surface, the coupling agents were found to have high modification ability. The modification produced a glass surface with high oxidation resistance.
α-Alkylation of α,β-Unsaturated Aldehyde Dimethylhydrazones Accompanied with the Double Bond Migration to β,γ
Authors: Yamashita Masakazu , Matsumiya Kaoru , Nakano Ken-ichi
Published: August 2006

Lithiated α,β-unsaturated aldehyde N,N-dimethylhydrazones reacted with alkyl halides accompanied by double bond migration to give α-alkylated β,γ-unsaturated aldehyde N,N-dimethylhydrazones in satisfactory yields. This reaction was found to be caused at the first step by deprotonation from a γ-carbon atom by lithium diisopropylamide. In the case of hydrazones with two kinds of γ-protons, deprotonation from the less hindered γ-carbon occurred selectively. Using this reaction, a novel sesquiterpene, 2,5,9-trimethyl-2-vinyl-4,8-decadienal, which has a vinyl group at the α-position, was synthesized in a good yield.
Photochromism of Viologen Hexacyanoferrate(II) Complexes via Intramolecular Electron Transfer
Authors: Nanasawa Masato , Kaneko Makoto , Kamogawa Hiroyoshi
Published: August 2006

Viologen metal complexes comprising 2,2′- and 4,4′-bipyridinium hexacyanoferrate(II) were synthesized starting from the corresponding halides by an anion-exchange reaction. The charge-transfer bands appeared in aqueous solutions, whereas radical cation peaks in visible region appeared in solid polymer matrices via a photoinduced electron transfer within the viologen molecule; their absorptions were dependent upon both the kind of bipyridinium dication and the media, such as the solvents and polymer matrices. The reversible redox reaction by photon mode (color development) and by heat mode (bleaching) can be repeated in the absence of atmospheric oxygen.
Intramolecular Photochemistry in β-Turned Dipeptide Bridged Molecules
Authors: Tamiaki Hitoshi , Kiyomori Ayumu , Maruyama Kazuhiro
Published: August 2006

Several benzophenone-β-turned dipeptide-alkyl chain molecules were prepared. In acetonitrile, intramolecular photochemical reaction of the synthetic molecules was investigated. The photoexcited benzophenone moiety abstracted selectively a hydrogen of the alkyl chain in the molecule. Such a site selectivity showed that the β-turned conformation might be rigid enough for the hydrogen abstraction in the excited state.
Synthesis and Properties of Bis[oxybis(methylenethio)]tetrathiafulvalene and Its Sulfur Analog: π-Donors for Organic Metals
Authors: Müller Harald , Ueba Yoshinobu
Published: August 2006

Bis[oxybis(methylenethio)]tetrathiafulvalene (BOBMT-TTF) and bis[thiobis(methylenethio)]tetrathiafulvalene (BTBMT-TTF) were synthesized in two steps starting from 1,3,4,6-tetrathiapentalene-2,5-dione. The electrochemical and donor properties of both compounds are discussed. BOBMT-TTF forms a highly conducting charge transfer complex with TCNQ (σRT   10 S cm−1).
Synthesis of 3-Cyano-6-hydroxy-5-[2-(perfluoroalkyl)phenylazo]-2-pyridones and Their Application for Dye Diffusion Thermal Transfer Printing
Authors: Matsui Masaki , Joglekar Bharati , Ishigure Yoshinao , Shibata Katsuyoshi , Muramatsu Hiroshige , Murata Yuukichi
Published: August 2006

New fluorine-containing azopyridone dyes, 3-cyano-6-hydroxy-5-[2-(perfluoroalkyl)phenylazo]-2-pyridones, have been synthesized. Though the introduction of a long perfluoroalkyl group lowered film forming ability and sensitivity, 5-[2-(trifluoromethyl)phenylazo]- and 5-[2-(perfluorobutyl)phenylazo]-3-cyano-4-methyl-6-hydroxy-2-pyridones showed good photostability.
Polymeric Organosilicon Systems. 16. Synthesis and Photochemical Properties of Poly[(1,2-dimethyl-1,2-diphenyl-1,2-disilanylene)naphthylenes]
Authors: Ohshita Joji , Ohsaki Hiroshi , Ishikawa Mitsuo
Published: August 2006

Poly[(1,2-dimethyl-1,2-diphenyl-1,2-disilanylene)-1,4-naphthylene], poly[(1,2-dimethyl-1,2-diphenyl-1,2-disilanylene)-1,5-naphthylene], poly[(1,2-dimethyl-1,2-diphenyl-1,2-disilanylene)-2,6-naphthylene], and poly[(1,2-dimethyl-1,2-diphenyl-1,2-disilanylene)-2,7-naphthylene] were synthesized by the condensation reaction of the corresponding bis(chloromethylphenylsilyl)naphthalenes with sodium. Photochemical properties of these polymers have been reported.
Preparation of a Voluminous Composite Oxide of BaLa2O4 and Its Catalytic Performance for the Oxidative Coupling of Methane
Authors: Yamagata Nobutsugu , Igarashi Kouji , Saitoh Hiroki , Okazaki Susumu
Published: August 2006

A voluminous composite oxide of BaLa2O4 was prepared by kneading powders of Ba(OH)2·8H2O (A) and La(NO3)3·6H2O (B) with a small amount of water, followed by pyrolysis at 1100 °C. The resulting material (apparent volume of ca. 3 cm3 g−1) was found to be effective as a catalyst for the oxidative coupling of methane to ethane and ethylene. The preparative conditions of the voluminous BaLa2O4 catalyst and these effects on the C2 formation were investigated. When reagents A and B were mixed with each other at 33 atom-% Ba and then calcined for 10 min at 1100 °C, the BaLa2O4 composite oxide was most advantageously produced and a high C2 yield of ca. 19% was reproducibly obtained over a non-pressed or voluminous catalyst. The high surface basicity and macro-porous structure of the voluminous BaLa2O4 catalyst, which were responsible for its high C2 yield, are discussed.
Induced Circular Dichroism of a Cationic Porphyrin Bound to α-Helical Poly(l-glutamic acid) and β-Form Poly(S-carboxymethyl-l-cysteine) in Aqueous Solutions
Authors: Nezu Takashi , Ikeda Shoichi
Published: August 2006

Absorption spectra and circular dichroism (CD) of aqueous solutions of a water-soluble porphyrin derivative, porphine-meso-tetra(4-N-methylpyridinium) tosylate (TMpyP tosylate), have been measured in the presence of poly(l-glutamic acid) or poly(S-carboxymethyl-l-cysteine) at different pH. At neutral and alkaline pH where poly(l-glutamic acid) is randomly coiled, essentially no CD is induced in the Soret region over a wide range of [P]/[D] ratios. At acid pH where poly(l-glutamic acid) is helical, a positive CD band at 415 nm and a stronger negative CD band at 442 nm are induced if [P]/[D] is high, but the induced CD is considerably weak as [P]/[D] is lowered, owing to partial disruption of the helical conformation by densely bound TMpyP ions, and it substantially vanishes at [P]/[D] as low as 1.

While random coil poly(S-carboxymethyl-l-cysteine) does not induce CD in the Soret region of TMpyP, β-form poly(S-carboxymethyl-l-cysteine) induces a weak, positive CD band at 510 nm, accompanied by an extensive weakening of the absorption bands.
Molecular Weight Dependence of the Properties of Chitosan and Chitosan Hydrogel for Use in Sustained-Release Drug
Authors: Kubota Naoji
Published: August 2006

Chitosan was treated with NaBO3 under a homogeneous condition in which it was previously dissolved in an aqueous acetic acid solution. Different molecular weight chitosan samples were obtained, depending upon the reaction conditions, NaBO3 concentration, reaction temperature, and reaction time. The performance of chitosan hydrogel for use in a sustained-release drug was investigated while focusing on the swelling properties of chitosan coated on a drug. Theophylline was used as a model drug to be released. Theophylline tablets were coated with respective chitosan samples, and then tested for the drug release rate. Each drug release obeyed zero-order or near zero-order kinetics, due to a reservoir system comprising a saturated theophylline solution and a chitosan hydrogel wall. The release rate of theophylline decreased with increasing the amount of coated chitosan, which affects the permeability of the drug, and increased with decreasing the molecular weight of coated chitosan, which affects the degree of hydration of the gel. A lag time effect was observed when higher molecular weight chitosan was coated. These experimental results were interpreted in terms of the degree of hydration of chitosan hydrogel and Fick’s law of diffusion.
Synthesis and Circular Dichroism Spectra of Sperm Whale Myoglobin-(57—96)-Tetracontapeptide
Authors: Hashimoto Chikao , Muramatsu Ichiro
Published: August 2006

A protected sperm whale myoglobin-(57—96)-tetracontapeptide (29) was synthesized by successive condensations of three fragments, Boc–(70 —76)–OH, Boc–(62—69)–OH, and Boc–(57— 61)–OH, to a partially protected eicosapeptide ester, H–(77—96)– OBzl. After removal of the protecting groups of 29, the crude product was purified with reversed-phase high-performance liquid chromatography to yield sperm whale myoglobin-(57—96)-tetracontapeptide (30). The circular dichroism spectra showed that this peptide was in a random conformation in 0.10 M phosphate buffer (pH 6.50) and in a 69% α-helix conformation in 60% 2,2,2-trifluoroethanol–0.10 M phosphate buffer (pH 6.50).
Corrosion Inhibition of Copper by 2-Mercaptobenzothiazole and Benzotriazole in Low-Conductivity Solutions
Authors: Zhou Guo-ding , Feng Yiqi , Wu Yiping , Notoya Takenori , Ishikawa Tatsuo
Published: August 2006

Corrosion inhibition of copper in a low-conductivity medium ( < 10 μS cm−1) containing benzotriazole (BTA) and/or 2-mercatobenzothiazole (MBT) was studied by using the AC impedance technique, Auger electron spectroscopy and corrosion tests. As the MBT concentration increased, the corrosion rate of copper abruptly rose to a peak, rapidly fell, and then finally decreased steadily. The maximum corrosion rate appeared at a MBT concentration of about 0.5 ppm. However, a concentration of more than 1.5 ppm MBT could effectively inhibit copper corrosion. The results from AC impedance measurements agreed with those from corrosion tests. The film resistance could be observed only when the MBT concentration was in excess of 1.5 ppm. A combination of BTA and MBT proved to be more effective than either compound used alone.
Spectroscopic Evidence for the Presence of an Inclusion Structure of Urea in Solution
Authors: Fukushima Kunio , He Hui Cheng
Published: August 2006

The FT-IR spectra of a valeric acid–urea–water system and a 1-butanol–urea–water system were measured. By comparing the spectra with those of related systems, an inclusion structure of urea molecules was found to exist in the solution state; the interpretation that the increase in the solubility of valeric acid or 1-butanol into water by the addition of urea is due to the existence of an inclusion structure was verified.
Gel Chromatography of Chlorophyllin (Cu–Na Salt) in Water and in Aqueous Poly(N-vinylpyrrolidone) Solution
Authors: Inamura Isamu , Uchida Kazutomo
Published: August 2006

Gel chromatography of chlorophyllin (Cu–Na salt) in water was compared with that in aqueous poly(N-vinylpyrrolidone) (PVP) solution. A shoulder at 430 nm in the absorption spectra, which was observed in all fractionated PVP solution system, is due to the monomer of chlorophyllin (Cu–Na salt). PVP tends to suppress aggregation of chlorophyllin (Cu–Na salt).
Synthesis and X-Ray Crystal Structure of 1-[Diphenyl(2-pyridyl)phosphoranylideneamino]-1H-1,3,5,2,4,6-trithia (5-SIV)triazine
Authors: Thomas Colacot J , Bhandary Krishna K , Thomas Leonard M , Senadhi Sobha E , Vijay-Kumar Senadhi
Published: August 2006

A 1 : 2 mole reaction between S4N4 and diphenyl(2-pyridyl)phosphine has given (NC5H4)Ph2P=N–S3N3 in 70% yield. Crystals of (NC5H4)Ph2P=N–S3N3 are monoclinic, space group P21/n with a = 11.543(8), b = 13.254(9), c = 13.636(5) Å, β = 104.65(6)°, and Z = 4. The structure is refined to a final R value of 0.057 using 2916 reflections [I > 2σ (I)]. The S3N3 ring is stacked against one of the phenyl rings with an average SN distance of 1.61 Å.
Photochemical Ring Closure of 10,10′-Disubstituted 9,9′(10H,10′H)-Biacridinylidenes Followed by Dehyrogenation
Authors: Yamada Sachiko , Kubo Maki , Fuke Hiromi , Tsubaki Noriko , Maeda Koko
Published: August 2006

The photolysis of 10,10′-disubstituted 9,9′(10H,10′H)-biacridinylidenes afforded the corresponding 7,16-dihydrobenzo[1,2,3-kl:6,5,4-k′l′]diacridines. The formation of photocyclized dihydrophenanthrene-type intermediates was confirmed spectroscopically.
Self-Assembly of a Macrocyclic Dinuclear Pd(II)–Phosphine Complex
Authors: Fujita Makoto , Yazaki Jun , Kuramochi Tadao , Ogura Katsuyuki
Published: August 2006

Reaction of a diphosphine ligand, bis[4-[2-(diphenylphosphino)ethyl]phenyl] ether (1) with Na2PdCl4 gave a macrocyclic dinuclear complex [PdCl2(μ-1)]2 (2) in a 58% isolated yield. The formation of 2 appears to result from a spontaneous self-assembly process under thermodynamic control, and thus, no special technique such as a high-dilution method was needed.
Electrochemical Oxy-trifluoromethylation of Butyl Acrylate
Authors: Sato Yasuhiro , Watanabe Shunsuke , Uneyama Kenji
Published: August 2006

Electrooxidation of trifluoroacetic acid in the presence of butyl acrylate in an MeCN–H2O–i-PrOH–(Pt) system under oxygen-bubbling provided a mixture of butyl 4,4,4-trifluoro-2-oxobutanoate and butyl 4,4,4-trifluoro-2-hydroxybutanoate.
Dehydrooligopeptides. XIV. Convenient Coupling of N-Carboxy-α-dehydroamino Acid Anhydride with Both Amine and Carboxyl Components
Authors: Shin Chung-gi , Honda Seiji , Morooka Katsuhiro , Yonezawa Yasuchika
Published: August 2006

In order to further develop and expand the usefulness of N-carboxy-α-dehydroamino acid anhydride (ΔNCA), the optimum conditions of the acylation of ΔNCA with N-protected α-amino acids (AA) were thoroughly examined. Furthermore, various kinds of AA or dipeptides as a C-component were utilized in the acylation of ΔNCA, followed by condensation with an AA methyl ester as an N-component.
Potassium Permanganate Oxidation of Ketone Oximes. A Deprotective Version
Authors: Wali Anil , Ganeshpure Pralhad A , Satish Sheo
Published: August 2006

KMnO4 in acetonitrile–water has been found to be a convenient system for regenerating ketones from ketone oximes under mild conditions.
Complexation of Alkyl Glycosides with Cyclic Resorcinol Tetramer in Apolar Organic Media: Geometrical Requirement for the Intracomplex Sugar–Sugar Interaction
Authors: Kikuchi Yasuaki , Toi Hiroo , Aoyama Yasuhiro
Published: August 2006

1H NMR and circular dichroism spectroscopic investigation of the complexation of octyl glycoside derivatives of various monosaccharides as guests with cyclic resorcinol tetramer as host in chloroform indicates that the complexation-responsible intracomplex sugar–sugar interaction is markedly dependent on the stereochemistry of the sugar glycosides.
Salt Effect for Accelerating Charge Separation from 9,10-Dicyanoanthracene–Stilbene Exciplex in Dichloromethane
Authors: Zhang Bao Wen , Kuriyama Yasunao , Cao Yi , Tokumaru Katsumi
Published: August 2006

On irradiation of 9,10-dicyanoanthracene (DCA) in the presence of cis-(CS) and trans-stilbene (TS) in dichloromethane, addition of tetrabutylammonium tetrafluoroborate efficiently accelerated production of the radical cations from CS and TS along with DCA radical anions.
Ester Interchange Reaction Catalyzed by Lanthanoid Tri-2-propoxides
Authors: Okano Tamon , Hayashizaki Yugo , Kiji Jitsuo
Published: August 2006

Lanthanoid tri-2-propoxides ([Ln(OPri)3]n Ln = La, Nd, Gd, Yb) are active catalysts for the interchange reaction of the alkoxyl groups between two kinds of esters. The La catalyst is the most active among them, and the activity is higher in nonpolar solvents than in polar ones. The La catalyst is applicable to the ring-opening polymerization of 6-hexanolide.
Optimum Cross-linking Spacer Length of Dimeric Neurokinin B Analogs for Interaction with NK-1 Tachykinin Receptors
Authors: Matsumoto Hiroshi , Shimohigashi Yasuyuki , Takano Yukio , Sakaguchi Kazuyasu , Kamiya Hiro-o , Ohno Motonori
Published: August 2006

A series of dimeric analogs of neurokinin B (NKB) COOH-terminal heptapeptide were synthesized in order to find an optimum length of cross-linking spacer for bivalent interaction with tachykinin receptors. Dimerization was carried out at the NH2-terminus of heptapeptide with succinyl bis[(Gly)n–OH], in which the number of glycine varies from 0 to 4. Dimers D–(Gly)n–NKB4—10, namely succinyl bis[(Gly)n–Asp–Ser–Phe–Val–Gly–Leu–Met–NH2] (n = 0—4), were almost inactive in the assay using rat vas deferens, indicating that they have no interaction with NK-2 receptor subtype. In contrast, these dimers were very active in guinea pig ileum (GPI) containing all of NK-1, 2, and 3 receptors. Relative activity was highest when the cross-linking spacer with oligoglycine of n = 2, and decreased sharply for dimers with shorter and longer chain lengths (n = 0 and 1; 3 and 4). In order to specify receptor subtype (NK-1 or NK-3) in GPI to which dimers bind, dimers were examined under the conditions that NK-1 receptors are desensitized by substance P methyl ester. All dimers exhibited drastically diminished contractile activity, indicating that dimers exclusively interact with NK-1. This was further confirmed by blocking the response of NK-3 receptors with atropine, which had no effect on the contractile activity of dimers. The results suggested that dimers interact bivalently with NK-1 receptors by bridging adjacent two binding sites.
Electrochemical Behavior of Azobenzene-4,4′-disulfonamide at Pyrolytic Graphite Electrode
Authors: Goyal R N , Srivastava Amit Kumar
Published: August 2006

The electrochemical reduction of azobenzene-4,4′-disulfonamide (1), an oxidation product of sulfanilamide, has been studied at Pyrolytic graphite electrode, over a wide pH range of 3.0 to 10.6 in the Britton Robinson buffers, by electrochemical and spectroscopic techniques. Under cyclic voltammetric conditions the 2e−, 2H+ reduction of this compound was found to give hydrazobenzene-4,4′-disulfonamide which has been characterised using IR, mp, mass and NMR spectra. Under controlled potential electrolysis, the presence of two electron withdrawing –SO2NH2 groups was found to cause the slow disproportionation [K′ = 3.29 × 10−3 s−1] of the hydrazo compound and sulfanilamide has been found as the major product of reduction. A plausible mechanism for the ECE reduction of 1 is suggested.
Absolute Stereochemistry of Dimethyl 9-(1,1-Dimethyl-2-phenylethyl)-9,10-dihydro-9,10-ethenoanthracene-11,12-dicarboxylate Rotamers
Authors: Toyota Shinji , Yamane Hideki , Oki Michinori
Published: August 2006

Absolute stereochemistry of the title compounds is determined through X-ray analysis of the 11-(−)-menthyl ester of the corresponding 11-carboxylic acid and its CD spectra are reported. Features of the molecular structure are discussed and revival of a term “absolute conformation” is proposed.
Isomerization of Caryophyllene Oxide Catalyzed by Solid Acids and Bases
Authors: Arata Kazushi , Hayano Kiyoharu , Shirahama Haruhisa
Published: August 2006

The reaction of caryophyllene oxide over eleven catalysts of solid acids and bases gave 4,5-dihydrocaryophyllen-5-one (III), (1R, 5S, 8R, 9R)-4,4,8-trimethyltricyclo[6.3.1.01,5]dodeca-2-en-9-o1 (IV), (2S, 5R, 9R)-caryophylla-1(12),8(15)-dien-9-ol (V), (2S, 5R, 9R)-caryophylla-1(12),7-dien-9-ol (VI), and (2S, 5R, 9S)-caryophylla-1(12)-7-dien-9-ol (VII). A large amount of III was formed together with IV over FeSO4 and Zr(SO4)2. Allylic alcohols (V, VI, and VII) were preferentially given by Al2O3–II and TiO2–ZrO2 in >74% selectivity: 96% on TiO2–ZrO2. Other catalysts formed three to five species of the products uniformly.