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The enantiomers, (R)-(-)-1 and (S)-(+)-1, of (+/-)-4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2,3- dihydro-2-methylbenzo[b]furan-7-carboxamide [(+/-)-1] were prepared from optically active benzyl 4-acetylamino-2,3-dihydro-2-methylbenzo[b]furan-7-carboxylate [(R)-(+)-6, (S)-(-)-6], respectively. The requisite (R)-(+)-6 and (S)-(-)-6 were prepared by large-scale preparative HPLC on chiral stationary phases (CSPs). The absolute configuration of (S)-(+)-1 was determined by single crystal X-ray analysis. The serotonin 5-HT4 receptor agonistic activity of (S)-(-)-1 hemifumarate (SK-951) which was hemifumarate of (S)-(+)-1 was about twice that of the other enantiomer (R)-(+)-1 hemifumarate which was hemifumarate of (R)-(-)-1.

X-Ray crystallographic analysis of two steroid derivatives, 5α,6α-epoxyphysalin B and 2,3-dihydrophysalin B, have been undertaken, revealing their closely similar crystal structures to each other. Their 1H NMR spectra, as well as that of the parent compound physalin B, a 13,14-seco-16,24-cyclosteroid from Physalis alkekengi, have been analyzed based on the crystal structures of these derivatives.

An extended molecular mechanics calculation of thermodynamic quantities, structure parameters, infrared absorption spectra, and Raman spectra of normal fatty acids was carried out on the basis of t...

(25R)-2,3,25,27-Tetrahydrophysalin A dimethanol solvate, C30H42O12, a derivative of 13,14-seco-16,24-cyclosteroid physalin A, crystallizes in the orthorhombic space groupP212121, witha=15.486(5),b=14.794(4), 12.248(6) A andZ=4. The crystal structure has been solved by direct methods, and refined to an R-value of 0.053 for 2345 observed reflections.1H NMR spectral data of physalin A and its hydrogenated derivatives measured in dimethylsulfoxide-d6 solutions have been elucidated, based on the crystal structure of the tetrahydrophysalin A, enabling the assignment of all the proton signals of physalin A. Theβ-proton of C(11)-methylene has been shown to resonate at remarkably higher field due to anisotropic shielding effect of carbonyl group at C(15).

The molecular mechanics simulation of the infrared absorption and Raman spectra of acetic acid in the solution or liquid phase has been carried out by using an empirically estimated force field which includes the equilibrium charges and the charge fluxes as the Coulomb potential parameters. The variation of the observed band widths among different normal modes has been taken into account by introducing the half band width parameters empirically assigned to individual internal coordinates. The half widths of more than 20 bands observed in the infrared absorption and the Raman spectra are well reproduced in terms of five half band width parameters. The thermodynamic properties and the structures of acetic acid monomer and dimer are successfully simulated. The overall features of the simulated spectra of acetic acid are in good agreement with the observed ones.

Three tirucallane-type triterpenoids, niloticin, phellochin and melianone, were isolated from the fruits of Phellodendron chinense SCHNEID. (Rutaceae). The stereostructure of niloticin was determined based on spectroscopic and X-ray crystal structure analyses. Furthermore, a derivative of niloticin and two derivatives of melianone were also found. A possible biogenetic pathway in P. chinense is proposed : niloticin → melianone → limonoids, on the basis of isolation of the compounds in different oxidation states.

The stereospecific synthesis is described of the first member of a new class of C-nucleoside analogues in which the sugar ring is replaced with a 1, 3-thiazolidine ring. The 1, 3-thiazolidin-2-yl analogues (1) and (2) of pseudouridine were prepared stereospecifically via condensation of L or D-cysteine with a formylated nucleobase.

A series of 10 didodecanoylamides of alpha,omega-alkylidenediamines bridged by a straight carbon chain varying in length from 0 to 9 carbons was examined as possible gelator molecules of organic liquids to gain information on the relationships between the spacial arrangement of two amide groups in a molecule and their effects on the microscopic structures of the gel. The structural characteristics of these amides are parallel and antiparallel arrangements of two amide carbonyl groups, which depend on the even and odd numbers of a bridging zigzag carbon chain. The linear alkyl chain moieties and a center carbon chain of diamides intermolecularly interact with each other within the van der Waals contact. Two amide moieties of an even number carbon chain diamide intermolecularly interact with each other by using two pairs of hydrogen bonds with two other molecules in a plane, which formed ribbonlike self-complementarily assembled aggregates. On the other hand, a diamide of an odd number carbon chain forms four independent hydrogen bonds with four other molecules not in a plane, which assembled into woven aggregates. Asymmetric introduction of a methyl group at the alpha-position of the amide groups successfully twists the two side chain van der Waals cores of the chiral diamides in the fixed direction, giving helically twisted ribbon and coiled coil aggregates. The helically twisted ribbon and coiled coil aggregates of these chiral diamides were directly observed by CD, SEM, and TEM, providing a basis for the design of a sophisticated small molecular gelator of a tailor-made shape.

The structure and stereochemistry of scopadulin, a novel aphidicolane-type diterpene isolated from Scoparia dulcis L. have been established from spectral data and single-crystal X-ray analysis of its acetone solvate.

X-ray crysal structures of two α-alkoxyglycine derivatives, Cbz–Gly(OR)–OR (R = Me and Pri), were determined. The structural and chemical characteristics of Gly(OR) residues as unique β-oxa analogs of α-amino acids are discussed.

Palladium (0)-catalysed reactions of N-alkylsulfonyl- or N-arylsulfonyl-3-alkyl-2-vinyfaziridines reveal that 2,3-cis-isomers are more stable than the corresponding 2,3-trans-isomers in accord with ab initio calculations.

Catalytic oxidation of ethylene glycol in an alkaline aqueous solution over a Pt/C catalyst by oxygen was studied in a slurry reactor at 40°C and ambient pressure. Under our experimental conditions, the interphase and intraparticle mass transfer resistances were found to be insignificant. The catalyst deactivation observed during the course of experiments can be ascribed to the formation of some oxidized species of platinum and/or to the adsorption of some by-products on the catalyst surface, and the decay of catalyst activity is consistent with a first order consecutive process, as described in the previous paper. The rate of reaction can be expressed by a power-law model under the conditions used. The orders of reaction with respect to ethylene glycol, sodium hydroxide and oxygen were estimated to be 0.20, 0.34 and zero, respectively. The mechanism of this reaction is discussed.

The kinetics and mechanism of vapor-phase ammoxidation of furfural to 2-furonitrile, and of 2-thiophenealdehyde to 2-thiophenenitrile, were studied over the Mo-Bi-Sb catalyst (molar ratio 3 : 5 : 2) in an integral flow fixed bed reactor under atmospheric pressure. The reaction temperature was 390°for furfural and 400°for 2-thiophenealdehyde. In both cases, the selectivity of nitrile was maximum with high conversion of aldehyde and the by-products formed were negligible in amounts. The reaction rate depended on the partial pressure of aldehyde and oxygen, but unaffected by that of ammonia. Model fitting was tried by the non-linear least square method, and the experimental data were well interpreted by the Langmuir-Hinshelwood mechanism, where the rate controlling step was the surface reaction between adsorbed aldehyde molecules and adsorbed oxygen molecules.

The catalytic activities of eight different types of triphase catalyst (immobilized phase transfer catalyst) were examined in the displacement reaction of several anions with benzyl bromide and n-octyl methanesulfonate at 70 and 90°C, respectively. The catalysts were prepared by the reaction of 1% cross-linked chloromethylated polystyrene with such tertiary amines as R3N (R=ethyl, n-propyl, n-butyl) and R (CH3)2N (R=ethyl, n-butyl, n-dodecyl, n-hexadecyl) and trin-butylphosphine. The catalytic activity for the reaction of n-octyl methanesulfonate increased with increasing size of the immobilized quaternary cation. The catalysts with bulky cations having different central atoms ([resin]-CH2N+(C4H9)3, [resin]-CH2P+(C4H9)3) showed almost the same catalytic activity in every reaction tested. Variation of the structure of the immobilized cation was concluded to modify the catalytic activity not only by changing the anion-cation interaction energy but also by changing the reaction environment around the active site.

The kinetics of liquid (organic)-liquid (aqueous) two-phase reactions on an immobilized phase transfer catalyst (triphase catalysis) was in vestigated. The displacement reactions of anions (aq. phase) on benzyl bromide or benzyl chloride (org. phase) were carried out at 90°C using tri-n-butylphosphonium chloride bound to 1% cross-linked polystyrene resin as a catalyst. The system was not stirred and all catalyst particles existed at the liquid-liquid interface. The observed sequence of nucleophilic reactivity of anions (CN-∼I->Br-, Cl-) is similar to that in a protic solvent. The reaction of benzyl bromide with potassium chloride was studied kinetically in detail. Under the experimental conditions used. all the mass transfer resistances had no significant effect and the rate of reaction was directly proportional to the amount of catalyst. The reaction order with respect to benzyl bromide was 0.73. From a consideration of the effects of concentrations of both chloride and bromide anions and the reverse reaction, a rate equation was developed.

The bromide ion displacement reaction of n-octyl methanesulfonate catalyzed by polymerbound phosphonium ion was studied and the effects of the phosphonium ion content and the degree of cross-linking on the intrinsic activity and the intraparticle diffusion were examined. The catalysts were prepared by quaternization of chloromethylated polystyrene with tri-n-butylphosphine. All experiments were carried out in a stirred tank reactor in the temperature range from 60 to 90°C and at ambient pressure. The intrinsic rate of reaction was proportional to the concentration of n-octyl methanesulfonate, and gradually increased with the concentration of potassium bromide in the aqueous phase. The intrinsic activity decreased with increases in the phosphonium ion content and the degree of cross-linking. The liquid-to-solid mass transfer resistance was insignificant at stirring speeds above 400 rpm under the present conditions. The intraparticle diffusion of n-octyl methanesulfonate was found to be an important factor controlling the global rate of reaction. The effective diffusivity of n-octyl methanesulfonate in polymer resin decreased remarkably with increase in the degree of cross-linking.

Diethanolamine was oxidized by gaseous oxygen to N-(2-hydroxyethyl) glycine in an aqueous solution containing sodium hydroxide over a 0.5% Pd-alumina catalyst in the temperature range of 50-80°C and at ambient pressure in a slurry reactor, and the kinetics was investigated. Under the present experimental conditions, all mass transfer resistances were assumed to be insignificant. The catalyst was very active but its activity decreased rapidly while it was in contact with oxygen. A power-law model was assumed for this reaction. The reaction order was estimated to be 0.37 with respect to diethanolamine concentration and 0.64 with respect to oxygen concentration. The rate was analyzed according to the Hougen-Watson model. It is concluded that the oxidation is mainly controlled by the surface reaction between adsorbed diethanolamine and oxygen in the liquid phase. This reaction is an excellent model for studies of three-phase reaction systems (gas-liquid-solid).

Ethylene glycol was oxidized to glycolic acid in an alkaline solution over a Pt/C catalyst, and data were collected at 40°C and ambient pressure in a liquid-full reactor. During a run, strong catalyst deactivation took place, but could be partly reversed by temporarily stopping the reaction or treating the catalyst with formalin. The catalyst activity could also be restored (though not completely) by oxidizing the deactivated catalyst with oxygen, followed by reduction with hydrogen. The deactivation of the catalyst is ascribed to the formation of some oxidized species (unknown) of platinum and/or to catalyst poisoning. The reactivation of the catalyst during the stopping period or on treatment with formalin is considered to be due to a reduction reaction between the oxidized species of Pt and ethylene glycol or formalin. The decay of catalyst activity is well described by a first-order deactivation process.

Vapor-phase synthesis of benzyl cyanide from 2-phenylethanol and ammonia was studied over Ni-Cu-SiO2 catalyst in the presence of hydrogen. Experiments were carried out in a flow reactor system under atmospheric pressure at 300°. The main product was benzyl cyanide, and toluene and phenethylamine were also produced. The Ni-Cu-SiO2 catalyst (Ni/Cu=3/1) gave the best selectivity for benzyl cyanide, 80%. The deactivation of this catalyst was negligible. By kinetic analysis, the rate of loss of 2-phenylethanol was found to show a first order dependency on the partial pressure of 2-phenylethanol, and was not affected by the partial pressures of ammonia and hydrogen. The experimental data were well interpreted by a model in which phenethylimine was produced as an intermediate and was then dehydrogenated to benzyl cyanide.

The oxidation of diethanolamine to N-(2-hydroxyethyl) glycine in alkaline solution was carried out over a Pd-Al2O3 catalyst in a liquid-full reactor, and the effect of mass transfer on the global rate of reaction was studied. Data were taken at 40°C and atmospheric pressure. Experiments were first done to determine the order of reaction with respect to oxygen, which was found to be 0.64 for an assumed tortuosity factor of 3.4 for the catalyst particles. Under the reaction conditions used, the effective mass transfer area between liquid and porous catalyst was found to be less than the outer surface area of the particles. With 0.5% Pd-Al2O3 catalyst, the global rate of reaction was mainly controlled by liquidsolid and intraparticle mass transfers, and the reaction was considered to be completed inside the deactivated outer shell, as the core of the particle still retained high catalyst activity.

The kinetics of heterogeneous vapor-phase ammoxidation of lutidine isomers was studied over a Cr2O3-Al2O3 catalyst in a flow system. The reaction was carried out at atmospheric pressure and at a temperature of 360°. 3-Cyano-5-methylpyridine, 4-cyano-3-methylpyridine, 2-cyano-6-methylpyridine, 2-cyano-5-methylpyridine and 2-cyano-3-methylpyridine were produced selectively at low conversion from 3, 5-lutidine, 3, 4-lutidine, 2, 6-lutidine, 2, 5-lutidine and 2, 3-lutidine respectively. 2-Cyano-4-methylpyridine and 4-cyano-2-methylpyridine were produced in same amounts from 2, 4-lutidine. The reaction rate depended on the partial pressure of lutidine and oxygen. Experimental rate data were well interpreted by Langmuir-Hinshelwood mechanism, where the rate determining step was the surface reaction between adsorbed lutidine molecules and adsorbed oxygen molecules.

The structures of four new isoatisine-type alkaloids, spiramines A, B, C, and D, isolated from Spiraea japonica L. fil var acuminata Franch, were determined.