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이승달,정종윤 陸軍士官學校 1999 한국군사학논집 Vol.55 No.-
Tropinone(1), which is key intermediate for the synthesis of cocaine(2), tropane spirohydantoin(3) and atropine(4), was effectively prepared by the acid-catalyzed reaction of 2,5-dimethoxy THF with methylamine and 1,3-acetonedicarboxylic acid under the reduced pressure. The reaction with N-alkyl substituted primary amine gave the N-alkyl substituted nortropinone as a sole product while, in the case of N-phenyl substituted primary amine, it involved the pyrrole as a side product as well as N-phenylnortropinone. The reactivity for the synthesis of N-substituted nortropinone was investigated.
"2,5-디메톡시테트라히드로퓨란과 이와 관련된 화합물들의 아세탈 교환반응"
이승달,정종윤 陸軍士官學校 1997 한국군사학논집 Vol.53 No.-
In the acid-catalyzed transacetalation of 2,5-dimethoxy THF, site selectivity was investigated as follows : 1) The reactions with alcohols in TMSC1 as catalyst gave 1,1,4,4-tetraalkoxybutane by the endocyclic C-O bond cleavage of 2,5-dimethoxy THF. 2) In the TMSCI and weakly basic Amberlyst A-21 resin as catalysts, the product was 2,5-dialkoxy THF by the exocyclic C-O bond cleavage of 2,5-dimethoxy THF. 3) In the reaction with ethylene glycol, it underwent in ipso-position to give 1,3-dioxolane ring formation, otherwise, in the reaction with 1,2-ethanedithiol, not in ipso-position to give bicylic system formation.
일차 디아미드로부터 디아실피롤화합물의 합성과 이들의 치환반응
이승달,이민수 陸軍士官學校 1997 한국군사학논집 Vol.52 No.-
Because of resonance interaction, the C-N bond of amides possesses partial double bond character. Chemically, this is manifested in the difficulty by which amides undergo hydrolysis, alcoholysis and aminolysis. In order to overcome those phenomena, primary diamides were converted to the corresponding N-acylpyrrole on the reaction with 1, 4-dichloro-1, 4-dimethoxybutane and weakly basic Amberlyst A-21 resin. The diacylpyrroles act as active diacylating agents.
이승달 陸軍士官學校 1996 한국군사학논집 Vol.50 No.-
In the [3C+3C] cycloaddition, a regiocontrolled cycloaromatization from two 3-carbon units, one with two nucleophilic sites and the other with two electrophilic sites, is developed.
티오세미카바자이드와 α - 할로카보닐 화합물의 위치선택적 반응
이승달 陸軍士官學校 2001 한국군사학논집 Vol.57 No.-
The condensation of thiosemicarbazide with a-halocarbonyl compounds gave 2-hydrazinothiazole and 2-amino-6H-1,3,4-thiadiazine derivatives, depending on the reaction temperature and reaction time, respectively. It was found that when the reaction mixture was refluxed overnight in H_2O, 2-hydrazinothiazoles were obtained in high yield. Otherwise, when it was carried out at room temperature or below room temperature, 2-amino-6H-1,3,4-thiadiazines were obtained within 1 hr in good yield. The proposed mechanisms for those reactions are described.
이승달,양일우 외2명 陸軍士官學校 1991 한국군사학논집 Vol.41 No.-
PMMA with narrow molecular weight distribution was recently obstained by using TASHF2 catalyst for anionic addition polymerization, named Group Transfer Polymerization(GTP). In this study, we have taken silyl enol either as initiator, methyl methacrylate(MMA) or methyl vinyl Ketone(MVK) as a monomer, and TiCl4 as a catalyst for cationic addition polymerization. The ratio of initiator: catalyst: monomer in good condition for PMMA was 1:4:15 in room temperature and the ratio of that for PMVK was 1:2:20 in the -15℃ or -78℃, in which gave the same result.
O-Heterobicyclic 화합물들의 합성에 관한 연구
李承達 陸軍士官學校 1986 한국군사학논집 Vol.30 No.-
비스-실릴이놀에테르의 고리형(1)과 사슬형(3) 화합물은 산성 조건하에서 아세톤과 2.5-디메톡시테트라히드로퓨란과 반응하여 각각 버스-락톤 화학물(8)과 두 고리형 화합물(10과 11의 혼합물)들을 합성했다. 이놀형 10과 케토형 11은 서로 도토메리 현상으로 존재해 있는 것이 아니라 서로 다른 입체 화학적 구조를 가지고 있음을 분광학적 판별과 관크로마토그래피 법에 의한 분리에 입증되었다.
1차 아민으로부터 N-치환된 2-Aminothiazole 유도체의 합성
이승달,이붕원 陸軍士官學校 1999 한국군사학논집 Vol.55 No.-
The most widely employed synthetic approach for the preparation of thiazoles is well-known as the condensation of an α-halocarbonyl compound with a reactant bearing the N-C-S fragment of thioureas, so called [3+2]mode. N-substituted thioureas were prepared by the reaction of primary amine with ammonium thiocyanate in the presence of acid and subsequently N-substitued 2-amino thiazoles were nicely synthesized by the reaction of chloroacetone with N-substituted thiourea in neutral condition. Benzidine-type rearrangement of 1-phenyl-2-[2'(4'-methylthiazole)]diazane(2c)was investigated.