Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 52 , Issue 6
Showing 1-50 articles out of 76 articles from the selected issue
  • Kozo Kozawa, Tokiko Uchida
    1979 Volume 52 Issue 6 Pages 1555-1558
    Published: 1979
    Released: April 19, 2006
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    Crystals of the 1 : 1 molecular complex of perylene–2,5-dibromo-3,6-dichloro-p-benzoquinone are triclinic, with a=8.669, b=9.697, c=7.321 Å, α=103.20, β=110.92, γ=64.60°, space group P\bar1, Z=1. The structure has been determined from diffractometer data by the heavy atom method and refined using the full-matrix least-squares method to R 0.069 for 2241 independent reflections. Stacks, with alternating donor and acceptor molecules, extend along the c direction. The acceptor molecule assumes two orientations, with a population ratio 1 : 1. A small degree of correlative change in the C–C bond lengths has been found in the perylene molecule on complex formation. The geometry of the quinonoid skeleton of the acceptor is similar to those of the anils and their complexes.
  • Michio Matsumura, Yoichi Nomura, Hiroshi Tsubomura
    1979 Volume 52 Issue 6 Pages 1559-1562
    Published: 1979
    Released: April 19, 2006
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    The photoelectrochemical behavior of sintered zinc oxide electrodes was studied. The intrinsic photocurrent, generated by ultraviolet illumination of the zinc oxide electrode, significantly diminished by grinding the electrode surface with an abrasive, and was restored by etching in 2 M(M= mol dm3)HCl for ca. 120 s. The dye-sensitized photocurrent caused by rose bengal was also lowered by grinding, but the effect was not as large as in the case of the intrinsic photocurrent, and the photocurrent was restored in a much shorter time of etching. The dye-sensitized photocurrent for an insufficiently etched electrode was enhanced by addition of a reducing agent, e.g., hydroquinone or allylthiourea. However, no enhancement was observed for a well etched electrode. The results, together with the luminescence and reflection spectra of zinc oxide, were discussed by means of models for the semiconductor electronic bands.
  • Yusaku Ikegami, Shozo Kubota, Hidetoshi Watanabe
    1979 Volume 52 Issue 6 Pages 1563-1567
    Published: 1979
    Released: April 19, 2006
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    1-Benzyl- and 1-(4-methylbenzyl)-4-methoxycarbonylpyridinyl radicals have been prepared by reducing the corresponding pyridinium iodides with sodium amalgam. Hyperfine structures of the ESR spectra were analyzed. The radicals were decomposed photochemically with visible light in the region 380–440 nm in order to generate the intermediate benzyl radicals which were identified spectroscopically at 77 K. Association of each radical at low temperature forms a diamagnetic radical dimer, which is transformed by irradiating the solution with 440–470 nm light into the triplet dimer with zero-field parameters, D=ca. 0.017 cm−1 and E≈O. Another radical, 1-(4-nitrobenzyl)-4-methoxycarbonylpyridinyl, is unstable at room temperature.
  • Harumichi Kobashi, Yasunaka Tomioka, Toshifumi Morita
    1979 Volume 52 Issue 6 Pages 1568-1572
    Published: 1979
    Released: April 19, 2006
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    Mechanisms of hydrogen atom abstraction by triplet p-chloranil [CA(T)] from 1,4-dioxane (DOH) and tetrachlorohydroquinone (CAH2) were studied in detail by means of nanosecond laser flash photolysis. A broad band around 740 nm in the transient absorption spectrum of CA in DOH was assigned to the charge-transfer band of the triplet EDA complex between CA and DOH. Efficiencies for the hydrogen atom abstraction from DOH and CAH2 were determined to be 0.13 and 0.58, respectively. The former value indicates that the hydrogen atom abstraction from DOH is less effective than a physical process in deactivation of the triplet complex. From the latter value together with the measured value of the quenching rate constant (1.7×109 dm3 mol−1 s−1) of the triplet by CAH2, it is inferred that the hydrogen atom abstraction of CA(T) from CAH2 takes place competing with an efficient radiationless deactivation via the triplet exciplex between CA(T) and CAH2 as a common intermediate.
  • Kazuo Yasukouchi, Isao Taniguchi, Hiroko Yamaguchi, Tatsuya Tanoue
    1979 Volume 52 Issue 6 Pages 1573-1577
    Published: 1979
    Released: April 19, 2006
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    The electrochemical behavior of N,N-dimethyl-m-toluidine (DMMT) in an acetonitrile solution at a Pt electrode was investigated. By controlled-potential oxidation at 0.65 V (vs. Ag/0.01 mol dm−3 AgClO4), the dihydro compound (I-a), which had been considered to be an intermediate in the reaction forming benzidine, was probably obtained. I-a was gradually converted to N,N,N′,N′-tetramethyl-2,2′-dimethylbenzidine (TMMB) in the solution within several hours. I-a was easily converted to TMMB by the cathodic re-reduction at −0.9 V or by adding either pyridine or water; this reaction pathway is useful for the synthesis of TMMB. Preliminary mechanistic information on the anodic oxidation of DMMT is also given by cyclic and ring-disk electrode voltammetry, current-reversal chronopotentiometry, and controlled-potential coulometry. The proposed reactions are: A–e→A\underset.+, A\underset.++A\oversetk→A-A\underset.+, and A-A\underset.+–e→DH22+, where A and A\underset.+ are, respectively, DMMT and its cation radical, DH22+ is the dihydro compound (I-a), and k is the rate constant of the coupling reaction (ca. 5×103 dm3 mol1 s1). TMMB is formed by: DH22++2e(or 2Py)→D+H2(or 2PyH+), where D is TMMB and Py is pyridine.
  • Kenzo Hiraoka
    1979 Volume 52 Issue 6 Pages 1578-1582
    Published: 1979
    Released: April 19, 2006
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    Clustering reactions of the protonated nitrogen N2H+ with hydrogen molecule, N2H+(H2)n−1+H2=N2H+(H2)n(n–1, n), were studied in a pulsed electron beam mass spectrometer with a high-pressure ion source. The values of enthalpy change −ΔSn−1,n(kcal/mol) and the entropy change −ΔSn−1,n(e.u.) obtained from the van’t Hoff plots of equilibrium constants were (0, 1) 7.2, 22.6, (1, 2) 1.5, 14.0. No cluster ions larger than N2H+(H2)2 were observed even at −187 °C. The relatively low values of enthalpy change for the clustering reactions (0, 1) and (1, 2) suggest that the positive charge in N2H+ is delocalized, the N2H+ ion very weakly interacting with additional hydrogen molecules electrophilicly. The calculated entropy change also suggests that hydrogen molecules in N2H+-(H2)n are weakly bound to the core ion N2H+, having considerable freedom of motion in the cluster ion. The thermochemical study proves that the cluster ion N2H+(H2)2 does not have the structure of the protonated hydrazine N2H6+.
  • Kazuhiro Matsubara, Yoshitsugu Oono, Shoichi Kai, Yukio Nishimura
    1979 Volume 52 Issue 6 Pages 1583-1587
    Published: 1979
    Released: April 19, 2006
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    For polyatomic quenchers there is a fairly accurate linear relation between σQ1⁄2 and r, where σQ is the quenching cross-section of rare gas metastables (especially Ar(3P2)) and r, the effective radius of the quencher.
  • Tanekazu Kubota, Hiroshi Miyazaki, Masumi Yamakawa, Kiyoshi Ezumi, Yos ...
    1979 Volume 52 Issue 6 Pages 1588-1596
    Published: 1979
    Released: April 19, 2006
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    The near-ultraviolet absorption spectra of various p,p′- and m,m′-disubstituted azoxybenzenes were recorded in aprotic and protic solvents. The PPP-SCFMO-CI calculation was used in analyzing the spectra and the solvent effect on them. The π-π* bands of azoxybenzene could be well interpreted on the basis of the electronic structure of benzaldehyde N-phenyl oxime (a nitrone). In addition, the half-wave potentials of reduction (E1⁄2red) and oxidation (E1⁄2oxd) were also measured in nonaqueous solvents. These electrochemical data and the above spectral data satisfied a good linear relation: (E1⁄2oxdE1⁄2red)=k1·Eho→luUV+k2, this equation having been previously proposed by us. In the Appendix, we have discussed the physical meaning of the constant term, k2, from the quantitative standpoint, using a series of alternant hydrocarbons as a typical example. Finally, a good linear relation between the E1⁄2red or E1⁄2oxd values and the substituent constants was demonstrated and discussed in azoxybenzenes.
  • Norihiro Matubayasi, Masatake Dohzono, Makoto Aratono, Kinsi Motomura, ...
    1979 Volume 52 Issue 6 Pages 1597-1600
    Published: 1979
    Released: April 19, 2006
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    The adsorption of dioctadecyl ether was studied at hexane/water interface, as functions of temperature, pressure, and mole fraction of dioctadecyl ether in hexane. The phase transition between expanded and condensed films was observed with decreasing temperature and increasing pressure and concentration. The thermodynamic quantities associated with the adsorption such as entropy, volume, and energy change were evaluated and comparison was made with the adsorbed films of 1-octadecanol at the same interface in which phase transition takes place. It is found that the dioctadecyl ether shows small negative discontinuous changes of the thermodynamic quantities with the transition from the expanded to the condensed films.
  • Yoshifumi Tanimoto, Kenji Inoue, Yoshihiko Furukawa, Yoko Segawa, Mich ...
    1979 Volume 52 Issue 6 Pages 1601-1605
    Published: 1979
    Released: April 19, 2006
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    The electronic interaction of both ground-state and excited-state m-aminoacetophenone (MAAP) with several aliphatic alcohols in nonpolar viscous solvent was investigated by steady-state and nanosecond fluorescence spectroscopies. Concentration dependence of several alcohols in liquid paraffin-hexane (LPH) mixed solvent upon fluorescence and absorption spectra suggests a complex formation of MAAP with aliphatic alcohols in the ground state. In the typical LPH solution of MAAP containing high concentration of alcohol, the complex fluorescence exhibits two-component decay and a longer wavelength fluorescence than the complex fluorescence exhibits a rise and decay. The results demonstrate that the complex in the excited state further associates with alcohol to make an exciplex including an alcohol molecule.
  • Isao Suzuki
    1979 Volume 52 Issue 6 Pages 1606-1613
    Published: 1979
    Released: April 19, 2006
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    A formalism has been developed for the calulation of vibration-rotation energy levels of linear XYZ and X2Y2 type molecules through direct numerical diagonalization of vibration hamiltonian matrix. The procedure of evaluating vibration as well as vibration-rotation energies can be described mostly in matrix algebra and thus easily converted to computer languages. The N2O molecule was chosen as an example of numerical treatment. Several approaches have been checked in evaluating Bv and Dv and they are discussed from the view point of accuracy and efficiency in computations. It is found that the variational approach of computing Bvr, contribution of rotational hamiltonian to Bv, is very efficient and accurate. Some peculiar features of the molecular potential of the X2Y2 type molecule are discussed in connection with their adaptation on the direct numerical diagonalization method.
  • Katsunori Nomoto, Yohji Achiba, Katsumi Kimura
    1979 Volume 52 Issue 6 Pages 1614-1618
    Published: 1979
    Released: April 19, 2006
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    A 304 Å HeII photoelectron spectrum of N2O4 in the gaseous phase has been deduced in the region up to 29 eV from a HeI spectrum of NO2–N2O4 mixture obtained with a nozzle beam technique, indicating three new maxima in the region between 20 and 29 eV. A 584 Å Hel spectrum of N2O4 was also obtained here. From a comparison of the HeI and HeII spectra of N2O4 below 20 eV, it was confirmed that two ionization bands exist at 16.5 and 18.2 eV which appear as shoulders in the HeII spectrum. At least fourteen ionization bands have been identified from the HeII spectrum in the region studied. The thirteen bands below 24 eV have been assigned on the basis of a recent Green’s function study of von Niessen et al.
  • Takeo Okamoto, Nobuo Nakamura, Hideaki Chihara
    1979 Volume 52 Issue 6 Pages 1619-1623
    Published: 1979
    Released: April 19, 2006
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    The existence of a “diffuse” phase transition below room temperature has been confirmed in N2H6SO4 crystal by powder X-ray and DTA experiments. The transition temperature is very sensitive to the grain size. This size effect was discussed on the basis of the thermodynamic nucleation theory taking into account the interfacial energy between the high and the low temperature phases. The diffuse nature of the transition was interpreted by a theory proposed by Tobolsky et al. The spin-lattice relaxation times of 1H were redetermined and the nature of the cationic motion in each phase was discussed.
  • Noriko Ohkami, Haruo Hosoya
    1979 Volume 52 Issue 6 Pages 1624-1633
    Published: 1979
    Released: April 19, 2006
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    The Wheland polynomials, the set of the numbers, w(G,j), of the j-th excited resonance structures, for a number of acyclic polyenes were calculated. The relations of w(G,j) with the non-adjacent numbers, p(G,k), topological index, ZG, and the total π-electronic energy, Eπ, were analyzed in detail for linear polyenes. For branched polyenes similar results were obtained, and it was found and proved that Eπ is linearly related with the number of Dewar (singly excited)structures. Method for the numbering of atoms to generate the canonical resonance structures was discussed.
  • Kojiro Kan, Yasushi Kai, Noritake Yasuoka, Nobutami Kasai
    1979 Volume 52 Issue 6 Pages 1634-1636
    Published: 1979
    Released: April 19, 2006
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    C15H11ON, M.W. 221.17, monoclinic, space group P21/c, a=9.451(1), b=8.267(1), c=14.336(2) Å, β=94.37(1)°, Dm=1.31, Dc=1.32 g cm−3, Z=4, R=0.088 for 1300 non-zero reflections. The molecule has an endo-configuration, and the furan ring has an envelope form.
  • Akira Kishioka
    1979 Volume 52 Issue 6 Pages 1637-1642
    Published: 1979
    Released: April 19, 2006
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    Several series of alkali (sodium and potassium) aluminophosphate glasses were prepared with compositions of 32–63 mol % of P2O5 and the properties of these glasses were determined. In the glasses with a higher P2O5 content (P2O5\gtrsim42.5 mol % in the Na2O–Al2O3–P2O5 glass and P2O5\gtrsim45 mol % in the K2O–A12O3–P2O5 glass), the density, refractive index, and chemical resistivity increased with increasing amounts of Al2O3. In the glasses with a lower P2O5 content (P2O5\gtrsim37.5 mol % in the Na2O glass and P2O5≈40 mol % in the K2O glass), however, almost no increase of the density was found by an increase of Al2O3; the increases in the refractive index and chemical resistivity were also smaller than those in the glasses with a higher P2O5 content. The infrared absorption spectra of the glasses varied also with the P2O5 content. These changes in the properties are due to a marked structural difference between the glasses with a higher P2O5 content and those with a lower P2O5 content, and are also associated closely with the structural role of Al3+ ions in the glass.
  • Akio Yuchi, Shinkichi Yamada, Motoharu Tanaka
    1979 Volume 52 Issue 6 Pages 1643-1647
    Published: 1979
    Released: April 19, 2006
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    The complexation equilibria of vanadium(V) with 8-quinolinolate ion(ox) were investigated spectrophotometrically. Depending upon the acidity of the solution various 1 : 1 and 1 : 2 complexes are formed: VO3ox2−, VO3Hox, VO2ox, and VO2ox2. The formation and protonation constants of these complexes are discussed in terms of their structures.
  • Tomikatsu Kudo, Yoichi Shimura
    1979 Volume 52 Issue 6 Pages 1648-1652
    Published: 1979
    Released: April 19, 2006
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    From the circular dichroism spectra of optically active dodecaammine-hexa-μ-hydroxo-tetracobalt(III) ion, (+)589-[Co{(OH)2Co(NH3)4}3]6+, measured in the visible and ultraviolet region in several solvents such as 0.01M-HCl and 0.17M-Na2SeO3, the d–d transitions of the complex are assigned in consideration of the ion-pairing effect. The absolute configuration of (+)589 isomer is assigned as Δ based upon a negative sign of the Ea component for the CoO6 chromophore. The circular dichroism change by the ion-pairing is attributed to the vicinal effect of chiral oxygen centers stereospecifically produced by the ion-pair formation, and the importance of the oxygen chirality is discussed on the basis of the time-course of circular dichroism change in the solutions.
  • Masao Tomoi, Takashi Hasegawa, Manabu Ikeda, Hiroshi Kakiuchi
    1979 Volume 52 Issue 6 Pages 1653-1656
    Published: 1979
    Released: April 19, 2006
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    Aqueous organic two-phase reactions (halogen exchange, cyanation, and borohydride reduction) have been catalyzed by phosphoric triamides containing hydrophobic groups. The phosphoric triamides, which have a high cation binding ability, exibited high catalytic activity for the two-phase reactions. The catalytic activity of N-alkylteramethylphosphoric triamides (1) was higher than that of the corresponding pentamethyl derivatives and the difference has been explained in terms of the contribution of the dimeric species of 1 and/or hydrogen bonding between the NH of 1 and the anionic moieties of inorganic reagents.
  • Chung-gi Shin, Yasuchika Yonezawa, Kazuo Unoki, Juji Yoshimura
    1979 Volume 52 Issue 6 Pages 1657-1660
    Published: 1979
    Released: April 19, 2006
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    Several pathways leading to ethyl α-azido-α-alkenoates (8) by the β-elimination to ethyl α-azido-β-substituted (hydroxy-, acetoxy-, or mesyloxy)-alkanoates with NaN3 or Et3N have been examined. The optimized procedure, in combination with subsequent reduction provides a general synthetic route to α-amino-α-alkenoic acid esters (9). The configuration of 8 and 9 have been shown to be of (Z)-geometry.
  • Toshiaki Sodesawa, Eisuke Ogata, Yoshio Kamiya
    1979 Volume 52 Issue 6 Pages 1661-1664
    Published: 1979
    Released: April 19, 2006
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    Disproportionation of propylene over MoO3–SiO2 (atomic ratio: Mo/Si=1/25) catalyst treated with HCl and aqueous ammonia was studied in the temperature range 350–600 °C under atmospheric pressure. The activity of MoO3–SiO2 catalyst extracted with aqueous ammonia remained for a long time, since most of free MoO3 was removed from the MoO3–SiO2 surface. This gave rise to increase in the selectivity for disproportionation of propylene to ethylene and butenes and decrease in the selectivity for hydrogenation, isomerization and polymerization. When MoO3–SiO2 not subjected to treatment was pretreated by H2 gas, it showed higher catalytic activity and lower selectivity for disproportionation than the one treated by N2 gas.
  • Shoichi Kusumoto, Kazuhiro Ikenaka, Tetsuo Shiba
    1979 Volume 52 Issue 6 Pages 1665-1671
    Published: 1979
    Released: April 19, 2006
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    Various structural analogs of N-acetylmuramyl-L-alanyl-D-isoglutamine, which had been shown to be the minimum structure required for the immunoadjuvant activity of bacterial cell walls, were synthesized in order to investigate in more detail the relationship between the activity and chemical structures. Particularly, the compounds of the structures corresponding to the cell walls of special bacteria without immunoadjuvant activity were prepared in this study. Several novel procedures including the preparation of a branched glutamyl peptide were newly exploited to accomplish the syntheses of muramyl peptides with complicated structures. As a result of this synthetic study, new informations were obtained on the structural requirement for the immunoadjucant activity.
  • Shoko Yoshimura, Kunitatsu Izumi, Yasutsugu Shimonishi
    1979 Volume 52 Issue 6 Pages 1672-1676
    Published: 1979
    Released: April 19, 2006
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    For a semi-synthesis of human lysozyme by coupling its natural fragment with synthetic peptides, a protected hexadecapeptide corresponding to positions 1–16 of the enzyme was constructed from three protected peptide fragments (V, IX, and XII) by the conventional method in pure state on the basis of analyses.
  • Shoko Yoshimura, Yasutsugu Shimonishi
    1979 Volume 52 Issue 6 Pages 1677-1681
    Published: 1979
    Released: April 19, 2006
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    For a semi-synthesis of human lysozyme by coupling its natural fragment with synthetic peptides, a protected tridecapeptide corresponding to positions 17–29 of the enzyme was prepared from three protected peptide fragments (II, VI, and XI) by the conventional method in pure form on the basis of analyses.
  • Motomichi Kono, Hiroshi Kihara, Nobuo Nakamura, Fumio Suzuki, Michinor ...
    1979 Volume 52 Issue 6 Pages 1682-1685
    Published: 1979
    Released: April 19, 2006
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    Barriers to exchange between dl and meso forms via rotation about the C9–Csubst bond of 9-(arylmethyl)-1,4-dimethoxytriptycenes are obtained by the use of the methoxyl signals in the 1H NMR spectra. It is found that, although the population ratios are affected by the substituent in the 9 position, the enthalpy of activation for the rotation is almost invariant at ca. 10 kcal/mol.
  • Michinori \={O}ki, Motomichi Kono, Hiroshi Kihara, Nobuo Nakamura
    1979 Volume 52 Issue 6 Pages 1686-1691
    Published: 1979
    Released: April 19, 2006
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    Benzyl methylene signals, which split into an AB quartet and a singlet and show temperature dependence, are obtained at various temperatures and are simulated with the use of two independent rates of rotation. Certain limitations of accuracy are found in this method. The uncertainty becomes less if additional data are provided from other sources, but never becomes negligible. Contribution of the slower process is found difficult to detect especially when the population involved in the process are the less.
  • Yoshio Inoue, Yukio Katôno, Riichirô Chûjô
    1979 Volume 52 Issue 6 Pages 1692-1697
    Published: 1979
    Released: April 19, 2006
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    The molecular dynamics of the inclusion complexes of cyclohexaamylose as a model of enzyme have been studied by means of carbon-13 NMR spectroscopy. As substrates we have chosen L-phenylalanine, L-tyrosine, L-tryptophan, glycyl-L-phenylalanine, and L-phenylalanyl-L-lysine. The molecular motion of both the cyclohexaamylose and the substrates in D2O–DCl solutions have been investigated by dividing the spin-lattice relaxation time into two contributions, the overall molecular reorientation and the anisotropic internal rotation. Upon complex formation, the correlation times for the internal motion of the phenyl ring of phenylalanine residue increase by a factor of up to 8, while those for the overall reorientation increase by a factor of only 2. These results indicate that the complex formation of the substrate with the cyclohexaamylose are induced by the insertion of aromatic side chain into a cavity of cyclohexaamylose even in the aqueous solution. The overall correlation times of the substrates are about three to seven times snorter than those of the host molecule. Thus the forces which bind the host cyclohexaamylose and the substrate are relatively weak. It was observed that the tightness of the inclusion varies with the types of aromatic amino acids and dipeptides.
  • Takayuki Suga, Tadashi Aoki, Toshifumi Hirata, Keiko Aoki (née ...
    1979 Volume 52 Issue 6 Pages 1698-1700
    Published: 1979
    Released: April 19, 2006
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    A novel C31 3,4-secodammarane-type triterpenoid, alnustic acid, was isolated from the male flowers of Alnus sieboldiana Matsum. (Betulaceae). Its structure was elucidated to be (12R,20S)-12,20-dihydroxy-24-methylene-3,4-secodammar-4(28)-en-3-oic acid by a combination of chemical and spectroscopic methods.
  • Arata Yasuda, Shin Tanaka, Hisashi Yamamoto, Hitosi Nozaki
    1979 Volume 52 Issue 6 Pages 1701-1704
    Published: 1979
    Released: April 19, 2006
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    The stereoselective route to the title insect hormones (JH-1 & JH-2) depends crucially on the epoxidation of allylic alcohols with t-butyl hydroperoxide in the presence of oxobis(2,4-pentanedionato-O,O′)vanadium(IV). The oxidation of 2-methyl-1-hepten-3-ol exclusively produces the (2R*,3S*) isomerofthe diastereomeric epoxy alcohols. This is converted into (Z)-6-methyl-5-undecene by the sequence involving oxirane reaction with lithium dibutylcuprate(I) and the removal of both hydroxyl groups of the resulting 1,2-diol. Extension of the series of reactions to the mono- and bisoxirane derived from (E,E)-farnesol gives JH-2 and JH-1, respectively.
  • Arata Yasuda, Hisashi Yamamoto, Hitosi Nozaki
    1979 Volume 52 Issue 6 Pages 1705-1708
    Published: 1979
    Released: April 19, 2006
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    Organoaluminum reagents of type R1R2NAlR2 allow highly stereospecific oxirane ring opening producing allylic alcohols under mild conditions. trans-Epoxycyclododecane is converted to (E)-2-cyclododecen-1-ol by reaction with diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP) in quantitative yield, while the cis-isomer gives only 8% yield of the same alcohol. Furthermore, this reagent enables us to perform the stereospecific isomerization of trisubstituted oxiranes: c-3-butyl-2-methyl-r-2-pentyloxirane is transformed into 2-pentyl-1-hepten-3-ol and the diastereomeric oxirane into (E)-6-methyl-6-undecen-5-ol, respectively. Such a rigorous stereospecificity is rationalized on the basis of a concerted syn elimination via the boat-like six membered ring imtermediary stage, in which the substituents of the oxirane ring should be arranged so as to minimize the severe nonbonded interactions.
  • Shinya Nomoto, Tetsuo Shiba
    1979 Volume 52 Issue 6 Pages 1709-1715
    Published: 1979
    Released: April 19, 2006
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    Six analogs of an antituberculous antibiotic capreomycin were synthesized in order to clarify the structure-activity relationship, especially with regard to the significance of the β-amino group in α,β-diaminopropionic acid residue as well as the position of linkage of the branch residue, β-lysine, to the cyclic peptide moiety. All the synthetic products were found to have the same conformations in solution as those of the natural antibiotics in terms of NMR spectra. It was found from their antibacterial activities that an amino group located at β-position of the α,β-diaminopropionic acid residue adjacent to ureidodehydroalanine residue remarkably strengthens the biological activity, and that the position of a branch does not significantly influence the antibacterial potency.
  • Noboru Ono, Tetsuji Yoshimura, Tadashi Saito, Rui Tamura, Rikuhei Tani ...
    1979 Volume 52 Issue 6 Pages 1716-1719
    Published: 1979
    Released: April 19, 2006
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    Active methylene compounds are selectively monoalkylated with alkyl halides in benzene using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a base. Selectivity of monoalkylation decreases when the reaction is carried out in a polar solvent. Ethyl acetoacetate is O-acylated with acyl halides in the presence of DBU in acetonitrile to give the (E)-enol esters stereoselectively.
  • Yasushi Yokoyama, Takahiko Tsuyuki, Yoshihiko Moriyama, Tatsushi Murae ...
    1979 Volume 52 Issue 6 Pages 1720-1722
    Published: 1979
    Released: April 19, 2006
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    D:A-Friedo-18β-lup-19-ene and D:A-friedo-18β-lup-19-en-3-one with a new migrated lupane framework were synthesized and the former compound was converted into known methyl trinorshionanoate.
  • Yukinori Nagao, Takahisa Misono
    1979 Volume 52 Issue 6 Pages 1723-1726
    Published: 1979
    Released: April 19, 2006
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    The sulfonation of 3,4-perylenedicarboximide (1) with sulfuric acid has been studied. The position of the sulfo group in the monosulfonated product (2) obtained at 100 °C has been discussed on the basis of the NMR and IR spectra of 2 and the related compounds, and has been confirmed to be the 9-sulfoperylene-3,4-dicarboximide. The localized treatment of 1 by H\ddotuckel and Pople MO calculations confirmed substitution at the 9-position. Paper chromatographic analysis indicated that the reaction product was only 2 in the temperature range 60–120 °C, and the reaction rate was determined spectroscopically. The maximum formation of 2 was approximatedly 97% at 100 °C. The rate of reaction was found to be a pseudo first order process and the activation energy found to be 19.5 kcal/mol.
  • Masato Nanasawa, Hiroyoshi Kamogawa
    1979 Volume 52 Issue 6 Pages 1727-1730
    Published: 1979
    Released: April 19, 2006
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    N-(8′-Apocarotene-8′-ylidene)butylamine (Bu-SB) has been protonated with amino acid derivatives in aqueous solution and the absorption maxima of the protonated products observed at 500 nm. Copolymers (from Nα-methacryloyl-L-lysine methyl ester and α-methyl N-methacryloyl-L-glutamate) bearing long conjugated double bonds as a side chain have been synthesized for the simulation of rhodopsin. The absorption spectra shifted to longer wavelengths, and the absorbances amounted to 4–8%, based on the maximum peaks.
  • Sadao Arai, Akira Tanaka, Mitsuhiko Hida, Takamichi Yamagishi
    1979 Volume 52 Issue 6 Pages 1731-1734
    Published: 1979
    Released: April 19, 2006
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    In the Ullmann condensation of bromoanthraquinones (AQBr) with ethylenediamine using copper(I) bromide as a catalyst, the reaction rate decreased with time which has been interpreted in terms of the formation of the ineffective copper(II) species. The kinetic investigation showed the reaction rate to be first order both for the copper(I) species and AQBr. After prolonged reaction the copper(I) species was quantitatively converted to the copper(II) species, the copper(II) species appearing to have little catalytic activity due to strong coordination with ethylenediamine. The reactivities of the haloanthraquinones were dependent on the ease of coordination with Cu(I) and the rate of Cu(II) formation. The mechanism, including the reaction between CuI(AQBr) and ethylenediamine, has been proposed and discussed.
  • Choji Kashima, Yasuhiro Yamamoto
    1979 Volume 52 Issue 6 Pages 1735-1737
    Published: 1979
    Released: April 19, 2006
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    By heating with various amines, the amino-exchange reaction of β-amino conjugated enones was regioselectively accomplished on β-carbon to give the corresponding β-amino conjugated enones. The resulting β-dialkylamino conjugated enones could then be used for the synthesis of β,β-disubstituted conjugated enones by treatment with Grignard reagents.
  • Kenji Yoshino, Yasukazu Ohkatsu, Teiji Tsuruta
    1979 Volume 52 Issue 6 Pages 1738-1742
    Published: 1979
    Released: April 19, 2006
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    Acetophenone α-methylbenzylhydrazone was produced by the thermolysis of 1,1′-diphenylazoethane in the presence of a cobalt complex in benzene. In this reaction, the cobalt complex seemed to stabilize the radicals formed from the azo compound by the elimination of α-hydrogen. The stabilized radicals underwent 1,3-rearrangement to form acetophenone α-methylbenzylhydrazone. The driving force of this rearrangement is considered to be the nature of the cobalt atom, which prefers a bond formation with a more electronegative nitrogen atom to a carbon atom.
  • Masashi Inoue, Yoshio Taguchi, Toshio Sugita, Katsuhiko Ichikawa
    1979 Volume 52 Issue 6 Pages 1743-1747
    Published: 1979
    Released: April 19, 2006
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    The temperature effects on the stereochemistry of the acid-catalyzed ethanolysis of trans-2,3-diphenyloxirane were examined. The stereochemistry of the reaction became more retentive as the reaction temperature was raised. The reaction mechanisms are discussed, and it is concluded that concurrent reactions take place in the ethanolysis, one of them giving an inverted product, and the other, a retained one, and that the former reaction is caused by a nucleophilic attack of ethanol on the carbon of the conjugate acid of the epoxide, while the latter proceeds via an intermediate which has a carbonium-ion character.
  • Shinji Kurokawa
    1979 Volume 52 Issue 6 Pages 1748-1751
    Published: 1979
    Released: April 19, 2006
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    As a modification for facilitating small-scale reactions, sodium N-methylanilinide was prepared from sodium hydride and N-methylaniline instead of by the usual method from sodium, N-methylaniline, and naphthalene (as assistant). Sodium N-methylanilinide, made by this procedure, was successively converted to sodium guaiazulenide, the formation of which was checked by tracing known reactions. The reaction of the reagent with 3-formylguaiazulene was also studied, and found to yield 4-substituted 2-formyl-1,4-dihydroguaiazulene and 6-substituted 2-formyl-3,6-dihydroguaiazulene. In this case, nucleophilic addition of guaiazulenide anion occured not at the carbonyl group but at the 6- and 8-positions of the seven-membered ring of formylguaiazulene, accompanied by formyl group and hydrogen migrations.
  • Arata Yasuda, Shin Tanaka, Hisashi Yamamoto, Hitosi Nozaki
    1979 Volume 52 Issue 6 Pages 1752-1756
    Published: 1979
    Released: April 19, 2006
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    The title synthesis involves (1) epoxidation of allylic alcohols with t-butyl hydroperoxide in the presence of vanadium catalyst followed by trimethylsilylation, (2) specific oxirane ring opening by means of diethylaluminum 2,2,6,6-tetramethylpiperidide and subsequent desilylation producing 3-ene-1,2-diols, and (3) removal of both hydroxyl groups through bromination with a mixture of phosphorus tribromide and copper(I) bromide and the successive zinc debromination. The sequence of reactions has been extended with considerable success to the preparations of β-myrcene from nerol, trans-β-ocimene from geraniol in a specific way, and α and β-farnesenes from their biological precursors. A C12 sex pheromone of red bollworm moth has been prepared efficiently by this method with cyclododecene as a starting material.
  • Arata Yasuda, Hisashi Yamamoto, Hitosi Nozaki
    1979 Volume 52 Issue 6 Pages 1757-1759
    Published: 1979
    Released: April 19, 2006
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    Reduction of glycidyl mesylate with dissolving metal produces allylic alcohol in fair to excellent yield. Combined with the highly stereoselective epoxidation of allylic alcohols with t-butyl hydroperoxide and oxobis(2,4-pentanedionato-O,O′)vanadium(IV) as a catalyst, the sequence provides a new and efficient means for 1,3-trans-position of allylic alcohols, by which geraniol is transformed into linalool, farnesol into nerolidol, and furthermore, (−)-cis-carveol into the (+) antipode and vice versa in a stereospecific way.
  • Michio Obayashi, Kiitiro Utimoto, Hitosi Nozaki
    1979 Volume 52 Issue 6 Pages 1760-1764
    Published: 1979
    Released: April 19, 2006
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    A novel procedure for preparing trisubstituted ethylenes stereoselectively is based on the reaction of α-trialkylsilyl-substituted ketones with alkyllithium reagents and on the following highly discriminative elimination of the silyl and oxido (or hydroxyl) groups from the resulting adducts. The syn-elimination of both groups is observed under basic conditions, while the reaction proceeds in anti-fashion on acid treatment. Furthermore α-trimethylsilylated ketones are shown to be readily obtained from 2-trimethylsilyl-2,3-dialkyloxiranes. The reaction sequence is applied to the stereoselective synthesis of tetrahomonerol which has been obtained from the codling moth.
  • Tsutomu Takagi, Masayoshi Oiwa
    1979 Volume 52 Issue 6 Pages 1765-1768
    Published: 1979
    Released: April 19, 2006
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    The difference in the hydrogen migration in urea and acetamide under electron impact has been discussed from the standpoint of the all-valence electron semi-empirical SCF-MO theory (CNDO/2). The features of the molecular ion in the ground state and the hydrogen-migration models for both compounds were estimated based on the variations in the total and the partitioned energies. The variation in the total energy with the hydrogen migration in urea was smaller than that in acetamide. Moreover, the bonding interaction between carbon and nitrogen becomes weak; the cleavage of the migrated molecular ion to NH3 was predicted. On the other hand, the weak bonding interaction between carbon and carbon in acetamide does not change through the migration of hydrogen. It is predicted that the α-cleavage in the C–C bond will occur in preference to the migration of hydrogen. Finally, in acetamide, it was found that the possibility of the migration of hydrogen is lower than that in urea, judging from the variations in the total and the partitioned energies.
  • Tsutomu Takagi, Masayoshi Oiwa
    1979 Volume 52 Issue 6 Pages 1769-1774
    Published: 1979
    Released: April 19, 2006
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    The hydrogen migration in butadiene under electron impact was studied by means of the calculated potential energy surfaces. The all-valence electron semi-empirical SCF-MO(MINDO/2-Unrestricted Hartree Fock) theory was employed. The possibility of the migration of hydrogen has been discussed. Moreover, the mechanisms (I–IV) including the hydrogen migration for the formation of the C3H3 ion have been discussed. The hydrogen-migration models are presented based on the variations in the total and the partitioned energies. It is very probable that the hydrogen on C1 in the M\underset.+ ion migrates to the other carbon, C4, via Models 1 and 2 in Mechanism IV. It was predicted that the formation of the C3H3 ion occurs by means of the fragmentation of the migrated M\underset.+ ion, although the other mechanisms can not always be ignored. Finally, for the hydrogen-migration models, the theoretical predictions were found to be in good agreement with the available experimental results.
  • Isao Taniguchi, Kazuo Yasukouchi, Akiko Yoshiyama, Taro Sekine
    1979 Volume 52 Issue 6 Pages 1775-1779
    Published: 1979
    Released: April 19, 2006
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    Rotating disk electrode voltammetry was applied to study the reduction mechanism of p-dimethylaminobenzaldehyde (1) in water–ethanol alkaline solutions by using a mercury-plated platinum rotating disk electrode. In the logarithmic analysis of the wave, the plots of log [i2⁄3/(idi)] vs. E showed good linearity, and the shifts of the half-wave potential with an increase in the rotation speed of the electrode (ω) and in the initial concentration of 1 (C) were ∂E1⁄2⁄∂logω=−22±2 mV and ∂E1⁄2⁄∂logC=19±2 mV, respectively. On the other hand, no appreciable change in E1⁄2 was observed with varying alkalinities of the solutions. These results and the large shift of E1⁄2 with an increase in the concentration of water (∂E1⁄2⁄∂log[H2O]=ca. 50 mV) are explained in terms of the following reactions:
    R+e\ ightleftarrowsR\ ewdot (solvated by water), (1)
    2R\ ewdot\oversetk→D2− (r.d.s.), (2)
    D2−+2H2O→DH2+2OH, (3)
    where R and R\ ewdot are the molecule and the radical of 1, respectively, D2− is the dimer of R\ ewdot and DH2 is the hydro-dimer (2) of R. The rate of the dimerization reaction (k in Eq. 2) was estimated to be 2.5×104 M−1 s−1 from the shift of E1⁄2 with logω for the 50% water-ethanol solution containing 1 M NaOH, and this rate constant decreased with decreasing water concentration.
  • Takashi Kawamura, Shigeru Hayashida, Teijiro Yonezawa
    1979 Volume 52 Issue 6 Pages 1780-1785
    Published: 1979
    Released: April 19, 2006
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    The bicyclo[2.1.1]hexan-5-yl and the 5-deuteriobicyclo[2.1.1]hexan-5-yl radicals have been examined using ESR. A comparison of the spectra confirmed that geometry around C5 is pyramidal and showed highly stereoselective long-range spin-transfer from C5 to the endo proton on C6; a(H6endo)=28.22 and a(H6exo)=0.49 G. A potential curve for the out-of-plane bending motion of the C5–H5 bond, selected from the trial curves gave a reasonable simulation of the temperature dependence and isotope effects on a(H5) and a(H6endo). The curve has two minima with a relatively low barrier to inversion; the geometry of the C5–H5 bond bent in the exo direciton has been estimated as approximately 0.9 kcal/mol more stable than that with the C5–H5 bond located in the endo direction.
  • Masatoshi Hirayama, Masashiro Owada
    1979 Volume 52 Issue 6 Pages 1786-1789
    Published: 1979
    Released: April 19, 2006
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    An approximate linear correlation has been found between the basicity of substrate (pKa) and the logarithm of the equilibrium constant K1 for 1:1 adducts evaluated from the least squares analysis of lanthanoid-induced shifts (LIS) for the systems containing Eu(fod)3 and a series of p-substituted anilines in CDCl3. In contrast, both the observed S-values and intrinsic shifts have shown no simple correlation to pKa’s of substrates.
  • Masakatsu Koshinuma
    1979 Volume 52 Issue 6 Pages 1790-1795
    Published: 1979
    Released: April 19, 2006
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    The details of electromotive-force measurement by means of a concentration cell consisting of sodium tetradecyl sulfate (NaTS) in ethanol–water mixtures and of anionic and cationic ion-exchange membranes as septams were described. The membranes used proved to be permeable exclusively to the surfactant (TS) and Na+ ions respectively. The activities of the TS and Na+ ions were measured separately, and then the mean activity was computed as a function of the ethanol content in the solvent. Below the CMC, the activities for TS and Na+ ions and the mean activity increased with an increase in the NaTS concentration, but decreased with an increase in the ethanol concentration. Above the CMC, the activity of the TS ion decreased, whereas that of the Na+ ion increased; the mean activity also slightly increased with an increase in the NaTS concentration. The values of CMC obtained were 1.5×10−3, 1.7×10−3, and 2.2×10−3 mol/dm3 for 5, 10, and 15 vol % ethanol concentrations respectively. The mechanism of mixed micelle formation was also expressed by a charged phase-separation model in an ethanol–water mixture much as in the case of a simple aqueous solution. The degrees of counterion attachment were found to be 0.73, 0.68, and 0.62 for 5, 10, and 15 vol % ethanol respectively. The intermicellar concentrations of TS, (CTS), and Na+ ions, (CNa), were calculated. With an increase in the NaTS concentration, CNa monotonously increased, but CNa decreased. At a given NaTS concentration, CNa increased with an increase in the ethanol concentration, while CNa was approximately constant.
  • Akira Kuboyama, Hitoshi Matsumoto
    1979 Volume 52 Issue 6 Pages 1796-1798
    Published: 1979
    Released: April 19, 2006
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    The π,π* absorption spectrum and its solvent effect of 2-methyl-1-indenone have been found to be similar to those of 1,2-naphthoquinone. This fact is discussed on the basis of the results calculated using the P-P-P method. The similarity of the calculated π-electronic structures in the low-energy π,π* singlet states between 1-indenone and 1,2-naphthoquinone is not so good as that between fluorenone and 9,10-phenanthrenequinone.
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