• Archives of Pharmacal Research
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• v.21 no.6
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• pp.793-795
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• 1998

• Journal of the Korean Chemical Society
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• v.68 no.3
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• pp.131-134
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• 2024

A simple strategy for the formal synthesis of the sex pheromone of gypsy moth (+)-disparlure from L-(+)-tartaric acid is described herein. The key steps include the mono-esterification and regioselective ring-opening of an epoxide using a Grignard reagent. The strategy of conferring asymmetry using 2-butanone enables mono-esterification in high yield and reduces the number of steps. Subsequently, (+)-disparlure is synthesized via the regioselective ring opening of the epoxide.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2869-2870
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• 2011

• Bulletin of the Korean Chemical Society
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• v.18 no.2
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• pp.133-134
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• 1997

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1741-1744
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• 2013

A new polymeric catalyst was prepared by supporting $GaCl_3$ on cross-linked polyvinylpyrrolidone ($GaCl_3$/PVP). This catalyst was employed for efficient and regioselective ring-opening reaction of epoxides by various alcohols under solvent-free conditions at room temperature. In our procedure, this heterogeneous catalyst was used at neutral and mild reaction conditions to afford high yields of ${\beta}$-alkoxy alcohols. Also, regioselective conversion of epoxides to ${\beta}$-azidohydrines was accomplished by sodium azide in MeOH in the presence of $GaCl_3$/PVP at room temperature. $GaCl_3$/PVP is a non-hygroscopic and recoverable catalyst and is easily separated from reaction mixture by a simple filtration and re-used repeatedly. Also, this catalyst has good handling and can be stored for long time without any reducing of its reactivity.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.881-888
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• 2004

By applying a catalytic amount of indium trichloride, regioselective ring-opening of epoxides to ${\beta}$-hydroxy ethers was established. While the alcoholysis of styrene oxides produed $S_N1$-type product, the alcoholysis of ${\alpha}$-heteroatom-substituted epoxides predominantly produced $S_N2$-type product.

• 한국전기화학회:학술대회논문집
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• 1999.04a
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• pp.27-27
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• 1999

• YAKHAK HOEJI
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• v.42 no.5
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• pp.500-506
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• 1998

Steroidal 2${\beta},\;3{\beta}$--epoxy compound was prepared from asiaticoside via six steps and reduced regioselectively with lithium aluminum hydride. Epoxide ring opening furnished 9 as a sole product at reflux condition through axial hydride attack at C-3.

• Korean Chemical Engineering Research
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• v.43 no.6
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• pp.647-661
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• 2005

The stereoselective synthesis of chiral terminal epoxide is of immense academic and industrial interest due to their utility as versatile starting materials as well as chiral intermediates. In this review, we investigate the research and development trend in the asymmetric ring opening reactions using cobalt salen catalysts. Hydrolytic kinetic resolution (HKR) technology is the very prominent way to prepare optically pure terminal epoxides among available methods. We have synthesized homogeneous and heterogeneous chiral dinuclear salen complexes and demonstrated their catalytic activity and selectivity for the asymmetric ring opening of terminal epoxides with variety of nucleophiles and for asymmetric cyclization to prepare optically pure terminal epoxides in one step. The resolved ring opened product combined with ring closing in the presence of base and catalyst afforded the enantioriched terminal epoxides in quantitaive yield. Potentially, these catalysts are using on an industrial scale to produce chiral intermediates. The experimental results of HKR technology applied to the synthesis of various chiral compounds are presented in this paper.

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.218-226
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• 2007

The stereoselective synthesis of chiral terminal epoxides is of immense academic and industrial interest due to their utility as versatile starting materials as well as chiral intermediates. In this study, new dinuclear chiral Co (salen) complexes bearing gallium-, indium- and tallium-chloride have been synthesized and characterized. The mass and EXAFS spectra provided the direct evidence of formation of dinuclear complex. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of various terminal epoxides having ether or ester groups by hydrolytic kinetic resolution technology. The easily prepared dimeric complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (> 99% ee). The dimeric structured chiral salen showed remarkably enhanced reactivity and may be employed substantially lower loadings than its monomeric analogues. The system described in this work is very efficient for the synthesis of chiral epoxide and 1,2-diol intermediates