• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.97-101
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• 1991

Gas-phase pyrolyses of carbonate esters, ${\alpha}$- and ${\beta}$-hydroxy esters and ${\beta}$-hydroxy ketones have been studied theoretically by the AM1 MO method. Carbonate esters were found to decompose by two types of processes; in the reaction pathway involving an intermediate, the decomposition of the intermediate was rate-limiting, but direct pyrolyses were also possible via a six-membered cyclic transition state in which the methoxy oxygen attacks a hydrogen atom on the ${\beta}$-carbon. The hydroxy esters and ketones were found to decompose in a concerted process involving a six-membered cyclic transition state. Successive methylation on the ${\alpha}$- and ${\gamma}$-carbon led to an increase in the reactivity in agreement with experiments.

• Journal of the Korean Chemical Society
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• v.37 no.9
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• pp.837-844
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• 1993

N-Arylmethylideneglycine N-oxide alkyl esters(1) were alkylated with alkyl halides in THF using lithium hexamethyldisilazide as a base, followed by hydroxylaminolysis to give N-hydroxy-${\alpha}$-amino acid esters(7).

• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.360-366
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• 1975

Selective reduction of carbonyl group with zinc borohydride in the presence of ester functional group was demonstrated with seven representative keto esters. Either hydroxy esters or lactones were obtained in good yields; ethyl 6-hydroxyheptanoate ($83.0{\%}$), ethyl 2,6-dimethyl-4-hydroxy-2-cyclohexenecarboxylate ($82.3{\%}$), ethyl p-(${\alpha}$-hydroxyethyl)-phenylacetate ($78.9 {\%}$), 4-phenylbutyrolactone ($70.2{\%}$), and 3-phenylphthalide ($92.4{\%}$) were obtained from the corresponding keto esters.

• Journal of the Korean Chemical Society
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• v.46 no.5
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• pp.479-485
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• 2002

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1619-1620
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• 2013

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.234.2-234.2
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• 2001

• Journal of Food Hygiene and Safety
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• v.4 no.1
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• pp.1-20
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• 1989

A survey for BHA (butyl hydroxy anisol), BHT(dibutyl hydroxy toluene), DHA (dehydroxy acetic acid), BA (benzoic acid), Sor. A. (Sorbic acid), POBA-Esters (P-hydroxy benzoic acid esters of ethyl, propyl, isopropyl, butyl and isobutyl), propionic acid, nitrite (as $N0_2$) and sulfites (as $S0_2$) of food additives which have much interesting to food consumers was carried out to assess the intake amount by Korean through the years of 1985-1987. Additive intakes were estimated by applying the determined a.dditive contents in the specific food to the specific daily food-intake amount obtained from the report of Korean national nutrition survey, and the level in cities were compared higher in general to that in rural communities, and the average level of the nation showed as follows; the estimated value of butyl hydroxy anisol and dibutyl hydroxy toluene in total was 0.017 mg, and 0.030 mg for dehydroxy acetic acid 0.064 mg for benzoic acid, 6.011 mg for sorbic acid, 0.247 mg for p-hydroxy benzoic acid eaters in total, 0.1438 mg for propionic acid 0.016 mg for nitrite ($N0_2$) and 0.022 mg for sulfite ($S0_2$) respectively, and those values were far below to that of FAO/WHO's ADls.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.256.1-256.1
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• 2001

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.578-581
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• 1989

Two enantiomers of various 2-hydroxy acid esters have been resolved as the 3,5-dinitrophenyl carbamates on chiral stationary phases (CSPs) derived from ${\alpha}-arylalkylamines.$ Two CSPs, each of which contains the same type of chiral moiety, but shows different mode of connection to a silica support, have been found to show the contrasting resolution behaviors. From the contrasting resolution behaviours of two CSPs used in this study, two competing chiral recognition mechanisms are proposed.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1169-1174
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• 1999

2-Diazo-1-naphthoquinone-5-sulfonyl chloride(NQD-Cl) was synthesized from sodium 2-diazo-naphthoquinone-5-sulfonate by chlorination. NQD-Cl was esterified with hydroxybenzophenones to give several 1,2-naphthoquinone-(2)-diazide-5-sulfonic acid ester derivatives(NQD-esters). We have compared benzophenone derivatives with methoxy group to benzophenone derivatives with hydroxy group. Solubility of each NQD-ester was studied. Each of NQD-esters was formulated with novolac base resin and PS plates were manufactured. Photosensitivity, bleachability, compatible exposed time and relative sensitivity were determined by UV spectrophotometry, imaged by UV lithographic techniques, and the gray scale method. According to the number of substituted NQD group, it showed that relative sensitivity was different from gray scale method. NQD-esters with methoxy group showed a good solubility and higher sensitivity than commercial PS ones.