• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.117-125
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• 1999

The alkylation benzene with 1-dodecene of Mordenite, Zeolite ${\beta}$ and Zeolite Y was studied in the stirring batch reactor. The kinds of zeolites were found to have influenced the reaction conversion and distribution of phenyldodecane isomer in the product. Compared to the alkylation conducted over Zeolite Y and Zeolite ${\beta}$, the alkylation over Mordenite exhibited higher distribution of 2-phenyldodecane and the alkylation conducted over Zeolite Y and Mordenite, the alkylation over Zeolite ${\beta}$ exhibited higher distribution of heavy alkylate which formed through oligomerization reaction readily deactivated the Lewis acid sites. A special feature of the effect of the benzene to 1-dodecene ratio the reaction conversion and selectivity of phenyldodecane isomer was found. At alkylation of benzene with 1-dodecene over Zeolite ${\beta}$, when the catalyst content in the system was high, the reaction will reach the optimal conversion at the higher B/D. When the benzene to 1-dodecene ratio was high, the selectivity of phenyldodecane isomer is high. It was also found that at the similar reaction conversion there was the same product distribution regardless of D/C ratio.

• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1375-1376
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• 2002

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2519-2520
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• 2009

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.749-757
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• 2002

Chiral oxazolidin-2-one is easily prepared from D-mannitol and demonstrated to undergo highly diastereoselective alkylation reactions via lithium imide Z-enolates of its N-acyl derivatives to afford ${\alpha}-branched$ products. Evans syn and non-Evans sy n aldol products were also selectively obtained using this new auxiliary in high diastereomeric purity by simply changing the stoichiometry of TiCl4 and the nature of the amine base. Also, this new auxiliary is employed in diastereoselective Staudinger-type ${\beta}-lactam$ syntheses. Using 2-chloro-1-methylpyridinium iodide as the dehydrating agent, the reaction of auxiliary tethered acetic acid with trans imines gave the desired ${\beta}-lactams$ with cis-selectivity.

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.769-772
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• 2002

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.112-112
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• 1989

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.895-901
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• 1999

The acid characteristics of ${\beta}$-zeolites was modified by the different calcination conditions in order to remove template and the post-treatments such as ammonium ion exchange and HCl treatment. Alkylation of benzene with propene and isopropanol was carried out over the catalysts to investigate the effect of acid characteristics on the selectivity to cumene in this reaction. The $Br{\ddot{o}}nsted$ acidity(IR $3610cm^{-1}$ band) of ${\beta}$-zeolite was significantly reduced by a deep bed calcination compared to that of ${\beta}$-zeolite calcined in a shallow bed. Moreover, extraframework aluminum species which did not show acidity were produced by the framework dealumination on the deep bed calcined ${\beta}$-zeolite. $Br{\ddot{o}}nsted$ acidity of deep bed calcined ${\beta}$-zeolite was significantly recovered by ammonium ion exchange, however, it was partially recovered by a weak HCl treatment. It was found that the framework aluminum as well as the extraframework aluminum were extracted by a strong HCl treatment. The selectivity to cumene was shown to be about 95% on the shallow bed calcined ${\beta}$-zeolite, however, it decreased to 90% on the deep bed calcined one. The post-treatment such as ammonium exchange and weak HCl treatment enhanced the selectivity to cumene up to 93% by the partial recovery of $Br{\ddot{o}}nsted$ acidity. Propene was proved to be a good alkylating agent for the selectivity to cumene compared to isopropanol.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1385-1391
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• 2004

A general route for the synthesis of optically active unhindered aliphatic alcohols, where the steric demands between two alkyl groups adjacent to the carbinol are similar, with high enantiomeric purity has been developed by sulfoxifation of chiral ${\beta}$-hydroxy sulfides, followed by alkylation and desulfurization.

• YAKHAK HOEJI
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• v.30 no.5
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• pp.238-244
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• 1986

As one of the starting materials, methylthioacetyl chloride(7) was synthesized in fair yield from mercaptoacetic acid via methyl methylthioacetate(5) prepared by alkylation employing N, N'-dicyclohexyl-O-methylisourea(4). Then 1-$\beta$-D-arabinofuranosylcytosine-5'-methylthioacetate (3) was prepared by esterification of ara-C with obtained methylthioacetyl chloride and tested for inhibitory activity on DNA synthesis in the growing primary hepatocytes and hepatoma strains($H_4$-II-E and HTC cells). In these in vitro cell lines, the inhibitory effect of ara-C-MTA(3) on DNA synthesis was similar to that of its parent ara-C but slightly lower.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.75-75
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• 1997

뛰어난 혈당강하작용을 가지고 있는 oxirane carboxilic acid의 analogue 합성과 관련하여 oxirane carboxilic acid의 기본골격을 용이하게 형성할 수 있고 동시에 다앙한 관능기를 갖는 side chain을 도입할 수 있는 방법을 개발함으로써 다양한 유도체들을 합성하는데 이용하고자 함. 방법 및 결과 $\alpha$,$\beta$-unsaturated ester로부터 dioxirane을 이용한 직접적인 epoxidation을 통해서 보통의 방법으로는 얻기 어려운 oxirane carboxilic acid의 ester를 높은 수율로 합성할 수 있는 방법이 개발되었으며 특히 분자내에 cpoxide 존재하에서도 Mitsnobu 방법을 이용한 O-alkylation에 의해 aryl ether 결합을 형성할 수 있는 방법이 개발되었으며 이들 방법을 이용하여 다양한 유도체들을 합성하였다.