A stereoselective synthesis of $1\beta-aminocarbapenems$ (11a-c) starting from-4-acetoxy-2-axetidinone derivative 4 is described. 4-Acetoxy-2-azetidinone derivative (4) was reacted with lithium enolate of benzophenone limine of glycine phenyl ester (5f) to give alkylated product (R)-6f in good yield with high diastereoselectivity. The alkylated procudt (R)-6f was transformed to thioesters (7a-c) by transesterification with thiols, Thioesters (7a-c) were converted to their oxalimides (8a-c), followed by the phosphite-mediated reductive cyclization to give carbapenems (9a-c). Removal of all protecting groups of carbapenems (9a-c) afforded $1\beta-aminocarbapenems$ (11a-c).

A method for calculating the main characteristics of a potentiometric titration curve in a carboxylic ion exchanger has been investigated. The potentiometric titration curves of simple electrolyte and ion exchangers (polyelectrolytes) showed a great difference between them. The acidity parameters of the ion exchangers, the thermodynamic constant (pK0), apparent equilibrium constant (K), and correction for the apparent equilibrium constant (b), were introduced and used to express the characteristics of the carboxylic ion exchanger. A characteristic equation related to the acidity parameters of the ion exchangers systems was derived. A fibrous carboxylic cation exchanger was used and potentiometric titration curves at different concentrations of the supporting electrolyte were obtained . To prove the validity of the characteristic equation, the concentration of the supporting electroyte was varied. In the present study, good agreement between the data points and the fitted curves was found in all the cases. The g (number of moles of alkali to 1 g of ion exchanger) of carboxylic ion exchanger was calculated from the concentration of supporting electrolyte (C), pH of the solution, and degree of neutralization of ion exchanger (x).

The spectral correction matrix has been established to study the simultaneous complextions between metals and a ligand, and it eliminated the mutual influence among the complexes. The two sensitive reations between iron(Ⅱ) and 1-(6-bromo-2-benzothiazolylazo)-2-naphthol(BBTAN) and zinc (Ⅱ) and BBTAN have been investigated and applied to the simultaneous determination of Zn and Fe at pH 8.5 in the presence of triton x-100. This method gave the simples determination of the characteristic constants of the complexes. For the analysis of natural water, foods and other samoles, the recoveries of Fe and Zn were between 92 and 109% and between 91 and 104%, and their relative standard deviations were less than 5.5 and 11%, respectively.

Magnesium isotope separation was investigated by chemical ion exchange with the 1-aza-12-crown-4 bonded Merrifield peptide resin using an elution chromatographic technique. The capacity of the novel azacrown ion exchanger was 1.0 meq/g dry resin. The heavier isotopes of magnesium were enriched in the resin phase, while the lighter isotopes were enriched in the solution phase. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assys. The separation factors of $^{24}Mg^{2+}$-$^{25}Mg^{2+}$, $^{24}Mg^{2+}$-$^{26}Mg^{2+}$, and $^{25}Mg^{2+}$-$^{26}Mg^{2+}$ were 1.008, 1.019, and 1.006, respectively.

Intramolecular ring-ring interactions in the model compounds, $8-methoxypsoralen-CH_2O(CH_2)n-adenine(MOPCH_2OCnAd$, n=2, 3, 5, and 6) in which 5' position of 8-methoxypsoralne (8-MOP) is linked by different polymethylene bridges to N9 of adenine, have been investigated by hypochromism measurements. Efficient ring-ring stacking interactions have been observed in $MOPCH_2CO2Ad$ (7) from the percent hypochromism(%H) and fluorescence spectra of the models and a reference molecule. The 8-methoxyposralen-adenine systems have shown stronger ring-ring stacking interaction than the psoralen-adenine system.

The potential anticancer agents, new anthracycline analogues (2-9) have been synthesized from the glycosides daunomycin (1a) and doxorubicin (1b). Compounds 2 and 6 were prepared by nucleophilic displacement esterification of a 14-bromodauomycin(1c) with sodium or potassium salts of butyric and all trans retinoic acid, respectively. Compounds 3 and 7 were obtained from daunomycin (1a) by direct amidation with a butyric and all trans retinoic acid in the presence of EDCI and PP, respectively. Compounds 4 and 8 were obtained from doxorubicin (1b) by reaction with the corresponding acids in the same manner. Compounds 5 and 9 were prepared from doxorubicin (1b) by acylation with two equivalents of the corresponding acids under the same reaction conditions.

The potential anticancer agents new anthracycline derivatives (2~9) have been synthesized from daunomycin (1a) and doxorubicin (1b) ad starting materials. Compounds 2 and 6 were prepared by the nucleophilic displacement type esterification of a 14-bromodaunomycin (1c) with a acetylsalicylic and palmitic acid in triethylamine, respectively. Compound 3 and 7 were obtained from daunomycin (1a) by direct amidation with the corresponding acids in the presence of EDCI and PP as esterification regents. Whereas 4 and 8 were prepared by reaction of doxorubicin (1b) with one equivalent of acetylsalicylic and palmitic acid using DCC/DMAP, respectively, 5 and 9 were obtained from 1b by acylation with two equivalents of the corresponding acids using EDCI/PP reagents.

The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

The molecular geometries and harmonic vibrational frequencies of dibenzofuran in the ground and lowest triplet state have been calculated using the Hartree-Fock and Becke-3-Lee-Yang-Parr(B3LYP)density functional methods with the 6-31G basis set. Upon the excitation to the lowest triplet state, the molecular structure retains the planar form but distorts from a benzene-like to a quinone-like form in skeleton. Scaled vibrational frequencies for the ground and lowest triplet state obtained from the B3LYP calculation show excellent agreement with the available experimental data. A few vibrational fundamentals for both states are newly assigned based on the B3LYP results.

A new polynuclear complex of manganese stearate has been prepared by substitution of acetate with stearic acid. The stearate ion with long alkyl chain was used to isolate molecular $Mn_{12}$ cluster from each other. The $Mn_{12}$-stearate compound prepared is soluble in most organic solvents and resistant against water catalyzed reduction. The $Mn_{12}$-stearate compound shows similar electrochemical, magnetic properties to the pristine $Mn_{12}$-acetate.

Split-flow thin (SPLITT) cell Fractionation(SF) is a technique that allows separation of particulates and macromolecules into two fractions. A gravitational SF(GSF) system is constructed and tested for its applicability for separation of dust and ground water particulates. When tested with polystyrene latex particles, experimental data were in good agreements with theory. The 9.8 and 21.4㎛ polystyrene particles were successuflly separated in a continuous mode, where the mixture is continuously fed into the GSF channel allowing separation in a large sacle. The GSF system is successfully applied to continuous separation of dust and ground water particels based on the sedimentation coefficient, which is closely related to the particle size. The separations were confirmed by microscopy and energy-dispersive X-ray (EDX) analysos.