• Journal of the Korean Chemical Society
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• v.9 no.2
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• pp.88-95
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• 1965

The exo adduct between furfuryl derivatives (furan, furfuryl acetate and furfuryl alcohol) and maleic anhydride were prepared in the presence of ethyl ether. The bromination of the exo adduct of each derivatives gave a monobromolactone and dibromoacid when the reaction was done in the presence of water. The formation of the bromolactone was proved to be dependent to the carboxylic participation to the incipient rearranged carbonium ion of a classical type, and the participation was sterically hindered by the steric structure of the substituents. The bromination of the furan-maleic anhydride adduct in the presence of organic solvent $(CCl_4,\;CH_2Cl_2)$ gave the dibromide, whereas the photochlorination of the same adduct in the presence of carbon tetrachloride gave the tetrachloride. The procedure of the preparation and the reaction path of the halogenation were described.

• Journal of Photoscience
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• v.8 no.2
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• pp.70-73
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• 2001

The chlorin-bromine building block was constructed and applied to synthesize $\delta$-bromo compounds of methyl pyropheophorbide-a. The visible spectra of the title compounds were discussed.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1800-1802
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• 2008

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.74-78
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• 1998

Synthesis of novel 9-fluoroanthracyclines carrying L-fucose as a sugar component is described. Compound 3 containing a fluorine at the C-9 position was synthesized from an epoxide 2 and HF/Pyr (7 : 3). Bromination and hydrolysis of compound 3 resulted in synthesis of an aglycone, 9-fluoroanthracyclinone 6. The α-(1b) and β -anomers (1a) of the final product were obtained in high yields by a coupling reaction with the L-fucose.

• Bulletin of the Korean Chemical Society
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• v.7 no.3
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• pp.210-213
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• 1986

1,1-Dicyano-2-ethoxycyclobutane (1a) was prepared by [2 + 2] cycloaddition reaction of vinylidene cyanide with ethyl vinyl ether. 1,1-Dicyano-2-phenylcyclobutane (1b) was prepared by the reactions involving the reduction of cinnamyl alcohol, chlorination, cyanomethylation, bromination, and ring-closure reaction. Compound 1a was ring-opening polymerized with NaCN or n-butyllithium to give a low molecular weight polymer. The compound 1b however, failed to polymerize by either anionic or radical catalysts.

• Bulletin of the Korean Chemical Society
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• v.6 no.6
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• pp.348-350
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• 1985

The compound 1,1,3,4-tetramethyl-1-sila-3-cyclopentene was obtained through the reaction of 2,3-dimethylbutadiene and dichlorodimethyl-silane in THF in the presence of sodium metal. After the bromination of this compound at $0^{\circ}C$ for 2 hrs and dehydrobromination by using a base, we prepared 1.1.3.4-tetramethyl-1-sila-2,4-cyclopentadiene, Which could undergo dimerization. The identification has been done by using $^1H-,^{13}C-$ and C/H-Correlation two dimensional nmr spectroscopies.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.349-355
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• 1995

Bromo-and chlorotrimethylsilane react with selenium dioxide in halocarbon solvents and generate selenium oxybromide and oxychloride, respectively. These in-situ generated oxyhalides turned out to be very efficient for selective bromination and chlorination of aldehydes and ketones. Under carefully controlled reaction conditions, second and third introduction of halogens into carbonyl compounds can be greatly suppressed, and high yields of monohalo compounds were obtained. The product ratios of this halogenation reactions can be best explained if the reactions are assumed to involve intermediate β-ketoselenenyl chlorides.

• Membrane Journal
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• v.27 no.6
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• pp.528-535
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• 2017

In this study, halogen element was introduced into polyphenylene oxide polymer using bromination reaction, and then halogen element was replaced with imidazolium. Imidazolium corporated polyphenylene oxide polymer was synthesized and the synthesis was confirmed by various instrumental characterization. In addition, gas permeation properties of $O_2$, $N_2$, $CO_2$ were studied with different imidazolium contents. As the content of imidazolium increased, the ion exchange capacity increased and the mechanical strength decreased. The gas permeance showed a tendency to decrease slightly with increaing imidazolium contents. Whereas, it was confirmed that the tendency of $CO_2/N_2$ ideal selectivity increased as the imidazolium contents increased.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.130-137
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• 2002

Microbial lactonohydrolases (intramolecular ester bond-hydrolyzing enzymes) with unique properties were found. The lactonohydrolase from Fusarium oxysporum catalyzes enantiose-lective hydrolysis of aldonate lactones and D-pantoyl lactone (D-PL). This enzyme is useful for the large-scale optical resolution of racemic PL. The Agrobacterium tumefaciens enzyme catalyzes asymmetric hydrolysis of PL, but the stereospecificity is opposite to that of the Fusarium enzyme. Dihydrocoumarin hydrolase (DHase) from Acinetobacter calcoaceticus is a bifunctional enzyme, which catalyzes not only hydrolysis of aromatic lactones but also bromination of monochlorodi-medon in the presence of H$_2$O$_2$and dihydrocoumarin. DHase also hydrolyzes several linear esters, and is useful for enantioselective hydrolysis of methyl DL-$\beta$-acetylthioisobutyrate and regioselective hydrolysis of methyl cetraxate.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.460-466
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• 2003

For the drug master file (DMF) of ketoconazole, four impurities (1-4) contained in ketoconazole were synthesized. During the synthesis of 2, a new synthetic method of 1,4-dihydropyrazine was established. To oxidize the aminoalcohol (2j) to the aminal (2j-1), the standard Swern oxidation condition was modified to mask the nucleophilicity of the amino group temporarily using one equivalent of acetic acid. Derivative 3 was synthesized via regioselective bromination at the 2 position of the 4-aminophenol derivative (3a) using $Br_2$ in the presence of p-TsOH. The etherification of aryl bromide with the phenol derivative (1f) was accomplished by a modification of the general Cu-mediated reaction condition using excess 1f itself as a solvent at elevated temperature (190 ℃).