From the aspect of their unique structures and important biological activities, highly functionalized ylactam natural products have attracted much attention to synthetic chemist in recent years. On the other hand, the usefulness of carbohydrate-derived enantiomerically pure building blocks to enantioselective synthesis of complex natural products has been well recognized. In this paper, we describe the synthesis of two highly functionalized γ-lactam natural products, PI-091 and epolactaene, in enantiomerically pure form. PI-091 was isolated from Paecilomyces sp. F-3430 by the group of Taisho Pharmaceutical Co. in 1990, and exhibits a platelet aggregation inhibitory activity against rabbit platelet in vitro. We started our total synthesis of PI-091 from D-glucose. In the early stage of this synthesis, all carbons in PI-091 were assembled by featuring an aldol carbon-elongation. Then an intramolecular ketalization and successive dehydration gave a 2, 4-alkylated furan, which was transformed to a γlactam skeleton by the photochemical singlet oxygen addition to the furan derivative, followed by a γlactone-γlactam transformation. The absolute structure of PI-091 was determined through the present synthesis. Epolactaene was isolated by Osada et al. from the culture broth of Penicillium sp. BM1689-P in 1995. It shows the neurite outgrowth activity of a human neuroblastoma cell line, SH-SY5Y cells. Owing to the similarity of their structures between PI-091 and epolactaene, we planned to synthesize epolactaene using the similar synthetic pathway employed to the total synthesis of PI-091. The synthetic achievements on these novel antibiotics are described herein.

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Dimethyl carbonate (DMC) is expected to be used widely, since it is a low toxic chemical. A novel preparation method of DMC, in which DMC is prepared via methyl nitrite (MN) by the oxidative carbonylation of methanol, has been developed. This method involves two separated reactions, those are, DMC synthesis and MN synthesis.
DMC is synthesized in gas phase from CO and MN over Pd (II) compound suppported catalyst with generating nitrogen monoxide (NO). The MN for DMC synthesis is synthesized from NO generated in DMC synthesis, methanol and O₂. As both of two reactions show high selectivities to DMC and MN, respectively, DMC is actually prepared from CO, methanol and O₂. According to this method DMC is prepared with high effiency and little catalyst deactivation since neither O₂ nor H₂O are present over the catalyst.

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The state of dissolved water in hydrophobic organic compounds such as decane (DAN), dibutyl ether (DBE), 3-decanone (DON) and methyl decanoate (MD) were studied by FT IR spectrosco py at 20°C, and examination was also made of the temperature dependence of this water in such solvents.
In DAN, the state of dissolved water was essentially that of water vapor.
In DBE, most of the dissolved water formed large clusters through hydrogen bond between ether groups and water molecules.
In DON, the diss olved water consisted of cluster I (dimer-trimer mixture), II due to hydrogen bond between ketonic group and water molecule, and III of liquid water.
In MD, this water was comprised of clusters I, II and III.
The cluster I in dissolved water were vaporized at 40°C to 80°C, large clusters II and III in dissolved water gradually split into smaller cluster with increasing temperature, though some still remainded.

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The homogeneous hydrogenation of different alkynes (1-hexyne, 2-hexyne, propiolic acid and dimethyl acetylenedicarboxylate) catalyzed by [RhH₂(Ph₂N₃) (PPh₃)₂] (dihydridorhodium complex)in several solvents (dimethyl sulfoxide (DMSO), N, N-dimethylformamide, tetrahydrofuran, acetone, benzene and toluene) under hydrogen at 1 atm, 303 K was studied.1-hexyne, 2-hexyne and dimethyl acetylenedicarboxylate were reduced, although propiolic acid was left unaffected. The highest activity was observed in DMSO, and the catalytic hydrogenation activity was found to decrease in the following order, 1-hexyne>2-hexyne>dimethyl acetylenedicarboxylate.1- and 2-hexyne could be selectively reduced to 1-hexene and cis-2-hexene respectively in essentially quantitative yields. The main hydrogenation product of the dimethyl acetylenedicarboxylate is dimethy maleate. The results are discussed in terms of the mechanism of partial hydrogenation of hexyne in DMSO.

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With the aid of stationary and time-resolved fluorescence spectroscopy, we investigated substituent effects on the intramolecular fluorescence quenching process in naphthylalanine derivatives (model compounds)1 that have naphthyl (electron acceptor) and dialkylamino (electron donor) groups at both ends of a propionamide chain. The effects of alkyl substituents (that were introduced into the donor moiety)on the rate and free-energy change (ΔG_ex) for the formation of a singlet-exciplex intermediate in methanol (MeOH) were explained in terms of steric and electronic effects of the alkyl substituents on the hydrogen-bonding solvation of the donor nitrogen in the locally excited singlet state and the stability of the exciplex intermediate. In addition, the alkyl substituent effects on the viscosity dependence of the A Ge. supported the view that the solvation of both the locally excited-state 1 and the exciplex intermediate plays a significant role in controlling the rate of the exciplex formation. On the other hand, the results of MM2 calculations and H-D exchange reactions for the model 1 and its reference compound substantiated the possibility that the spacer moiety interconnecting the acceptor and donor groups adopts a relatively rigid conformation and thereby requires at best only a small conformational change on production of a given exciplex intermediate. Activation parameters for the singlet exciplex-forming process in MeOH provided strong evidence for the occurrence of hydrogen-bonding solvation in the excited singlet-state model compounds. The enhanced steric hindrance of the alkyl groups attached to the tertiary amino nitrogen resulted in a decrease in the ability of this nitrogen atom to form a hydrogen bond with a MeOH molecule, being reflected in the decreased activation enthalpy and entropy. However, replacement of the 1-naphthyl acceptor in 1 by the 2-naphthyl exerted a negligible effect on the activation parameters.

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Thermal properties of tri (o-toly)bismuth (Bi(o-Tol)₃) used as a bismuth precursor for metalorganic chemical vapor deposition (MOCVD) were evaluated. The saturated vapor pressure of Bi (o-Tol)₃ was observed under the decomposition point, about 210°C by means of vapor pressure measurement. The temperature dependence of the saturated vapor pressure of Bi(o-Tol)₃ was determined as follows, log P(_evap.)_Torr=-6267/T+13.45. It was confirmed that Bi (o-Tol)₃ has higher thermal stability compare d with a conventional bismuth precursor, triphenylbismuth (BiPh₃) by thermogravimetry and differential thermal analysis measurements of the compounds before and after preparation of oxide thin films by MOCVD method.

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Industrially available poly (bisphenol A arenedicarboxylate) (polyarylate) is conventionally produced by the interfacial condensation polymerization of bisphenol A and the mixture of terephthaloyl/isophthaloyl chlorides. We now report a new synthetic method without using the acid chloride derivatives, and the synthesis of oligomeric arenedicarboxylate by the melt condensation polymerization of bisphenol A and diphenyl terephthalate/isophthalate (mole ratio of reactants is 1/0.5/0.5). By removal of phenol from the reaction mixture, we obtained oligomeric ester, which can be changed to a high molecular weight polyester in the subsequent reactions. This report discussed the kinetics of the melt condensation of bisphenol A and diphenyl terephthalate/isophthalate mixtures. The melt condensation polymerization of bisphenol A and diphenyl terephthalate/isophthalate was analyzed by the bimolecular reaction of OH and a phenyl ester. The activation energy was estimated to be 32.2 kcal/mol. The relationships between the reduced viscosity and molecular weight was estimated and the following experimental equation was obtained; η_sp/C=7.46×10^-5_??_. Polymer was analyzed by ¹H-NMR, and the ratio of the end group of the hydroxy group to phenyl ester group was determined. FD-MS suggested four types of oligomeric ester end groups: phenyl-phenyl, phenyl-hydroxy, hydroxy-hydroxy, and cyclic.

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Cotton/polyester (C/P) blended yarn fabrics were treated with several flame retardants used for poly (ethylene terephthalate) (PET) using pad-dry-cure method. The relationships between the chemical structures of the flame retardants and their partition into PET fibers were investigated. When tetrabromobisphenol A (TBP-A) was tested, the amount of sorption increased with increasing concentration of TBP-A in treating acetone solution, and reached 4.0%o. w. f. (% on the weight of the fibre) at 10 wt%. This treated fabric was again treated with a flame retardant for cotton, Pyrovatex CP New, which contains dimethyl 2- (N-hydroxymethylcarbamoyl) ethylphosphonate as a main component. However, sufficient flame retardancy was not obtained. The second partition of TBP-A to cotton during heating was thought to lower the sorption efficiency of Pyrovatex CP New. Based on this assumption, for the case of the two-component sequential treatment, the Pyrovatex CP New treatment, which generates covalent bonds with hydroxy groups of cellulose, should be carried out prior to the TBP-A treatment. When a C/P blended yarn fabric was treated with Pyrovatex CP New and then with TBP-A, the amount of sorption of Pyrovatex CP New was 9.6%o. w. f. and the amount of sorption of TBP-A was 4.6%o. w. f. The limiting oxygen index of the treated fabric was 27.2%, a sufficient value for flame retardancy. From this result, it was concluded that the practical flame-retardant finishing of C/P blended yarn fabrics could be carried out by using a simple finishing machine.

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The bis (sulfophenyl) phosphonate-formaldehyde resin was prepared by the reaction of diphenyl phosphonate-formaldehyde resin with fuming sulfuric acid. This resin was used as an acid catalyst for esterification of saturated secondary alcohols with saturated fatty acids. The yields of the esters formed with saturated secondary alcohols (C₃CC₉) and saturated fatty acids (C₂O₅) were about 70-80% at 100°C. The yields of esters formed with saturated secondary alcohols (C₃C₉) with saturated fatty acids (C₆C₉) were about 60-80% at 100°C except a few esters of higher alcohols and higher fatty acids.

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Oxidation of 1, 4-dialkoxy-5, 8-dimethoxynaphthalenes (1) with ammonium cerium (IV) nitrate (CAN) gave two regioisomeric quinones whose ratio was affected by an electronic difference between methoxy and alkoxy groups. Substrates having electron-donating alkoxy groups as compared with methoxy ones gave mainly 5, 8-dimethoxy-1, 4-naphthoquinone (3); the minor was 5, 8-dialkoxy-1, 4naphthoquinone (2). On the other hand, substrates bearing electron-withdrawing groups preferentially afforded 2. Oxidation of 1, 4-diacetoxy-5, 8-dimethoxynaphthalene (1i) with CAN gave only 5, 8-diacetoxy1, 4-naphthoquinone (2i).

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