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RISS 인기검색어
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Northebaine에 Diels-Alder반응을 이용한 새로운 Thebaine 유도체의 합성
김근재,김계광,Kunjea Kim,Kyekwang Kim 대한화학회 1988 대한화학회지 Vol.32 No.4
Thebaine과 diisopropyl azodicarboxylate을 반응시켜 northebaine을 합성한 다음 thebaine의 diene에 nitrosobenzene을 dienophile로 하여 Diels-Alder반응을 시도한 후 가수분해하고 succinic anhydride와 chloroacetyl chloride를 각각 반응시켜 14-carbon에 새로운 치환기인 phenylhydroxylamine과 17-nitrogen에 acyl group을 도입한 새로운 화합물(16-A)와 (16-B)를 각각 22와 16%의 수율로 얻었다. Thebaine was reacted with diisopropyl azodicarboxylate to give northebaine. Diels-Alder reaction between the compound and nitrosobenzene was attempted. The hydrogen of the adducted northebaine was substituted with chloroacetyl chloride and succinic anhydride. We have synthesized the new thebaine derivatives with phenylhydroxylamine at 14-carbon and also acetyl or succinyl at 17-nitrogen with yields of 22% and 16%.
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The Reaction between Organothioenamine Phosphonate and Styrene Oxide
김근재,한치선,Keun Jae Kim,Chi Sun Han Korean Chemical Society 1976 대한화학회지 Vol.20 No.4
The fact that a reaction between organothioenamine phosphonate and styrene oxide produces a derivative of cyclopropane has been proved by structural identification. This suggests that an anionic oxygen atom from the ring opening of the styrene oxide by nucleophilic attack of thioenamine phosphonate links to the phosphorous atom to from a betaine as an intermediate which is followed by cleavage of the weak P-C bond. The dextrorotatory optical activity of the product showed that the reaction was under the control of steric stability of the benzyl carbon in styrene which leads to the product through a sterically stable pathway. Organothioenamine phosphonate와 styrene oxide 와의 반응에서 얻어진 생성물의 구조를 규명한 결과 그것이 cyclopropane 유도체임을 알았다. 이것은 반응이 styrene oxide에 대한 thioenamine phosphonate의 친핵공격에 의해서 생긴 산소 음이온이 다시 인 원자를 공격함으로서 중간체로 betain이 형성 된다음 이어서 약한 P-C 결합이 끊어지면서 생성물로 이끌어져 감을 가리켜 주고있다. 또한 생성물의 광학활성을 조사한 결과는 우회전성 이어서 이 반응은 중간체에서 생긴 benzyl carbon의 입체적 효과를 받으며 어디까지나 안정한 경로를 거쳐서 이끌어져 감을 알 수 있었다.
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Aclacinomycin A의 Aglycone의 유도체들의 합성
김근재,김호식,Kim Keun Jae,Kim Ho Sik 대한화학회 1990 대한화학회지 Vol.34 No.5
항생항암제인 Aclacinomycin A의 aglycone 부분인 aklavinone(2)의 유도체인 7-deoxy-9-methyl aklavinone(3)을 합성하였다. 7-Deoxy-9-methyl aklavinones, the derivatives of aklavinone (the aglycone of extensive family of glycosidically derived from anthracycline antibiotics possessing significant activity), were synthesized by the simple and efficient reaction procedure.
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초등 온라인 환경에서 교육용 인공지능 도구를 활용한 메이커 수업 설계 및 효과
김근재,한형종,Kim, Keun-Jae,Han, Hyeong-Jong 한국디지털정책학회 2021 디지털융복합연구 Vol.19 No.6
코로나19로 인한 온라인 학습이 확대되고 있는 상황에서 기존 메이커 교육은 학교 수업 현장에 적용하기에 한계를 지닌다. 본 연구는 초등학교의 온라인 환경에서 교육용 인공지능 도구를 활용한 메이커 수업을 설계하는 목적을 지닌다. 또한, 이에 대한 반응 확인과 함께 학습자의 컴퓨팅 사고력, 창의적 문제해결력 향상에 도움이 되었는지를 살펴 보고자 하였다. 이를 위해 선행연구 검토와 교육과정의 재구성을 통해 수업을 설계하였다. 면담을 통한 교수자와 학습자 반응 확인, 대응 표본 t검증을 활용한 사전-사후 분석이 이루어졌다. 연구 결과, 초등 온라인 환경에서 교육용 인공지능 도구를 활용한 메이커 수업은 공감하기, 메이킹 문제 정의하기, 재료 및 도구 특성 파악하기, 리믹스를 활용한 알고리즘 설계 및 코딩하기 등을 포함한 총 10단계로 구성된다. 학습자의 컴퓨팅 사고력과 창의적 문제해결력에 대한 사전-사후 분석 결과, 통계적으로 유의미한 차이가 나타났다. 본 연구는 초등교육 맥락에서 교육용 인공지능 도구를 활용한 실제적인 메이커 활동이 온라인 환경에서도 실제적으로 적용 가능하다는 점을 확인한 의미를 지닌다. In a situation where the online learning is expanding due to COVID-19, the current maker education has limitations in applying it to classes. This study is to design the class of online maker education using artificial intelligence tools in elementary school. Also, it is to identify the responses to it and to confirm whether it helps improve the learner's computational thinking and creative problem solving ability. The class was designed by the literature review and redesign of the curriculum. Using interveiw, the responses of instructor and learners were identified. Pre- and post-test using corresponding sample t-test was conducted. As a result, the class consisted of ten steps including empathizing, defining making problems, identifying the characteristics of material and tool, designing algorithms and coding using remixes, etc. For computing thinking and creative problem solving ability, statistically significant difference was found. This study has the significance that practical maker activities using educational artificial intelligence tools in the context of elementary education can be practically applied even in the online environment.
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초등학교에서의 피지컬 컴퓨팅 도구를 활용한 메이커 교육 수업 모형 개발 연구
김근재 ( Keunjae Kim ),임철일 ( Cheolil Lim ) 한국교육공학회 2019 교육공학연구 Vol.35 No.3
The purpose of this study is to develop an instructional model and strategies for maker education using a single-board computer(SBC) in elementary school. Despite the increasing emphasis on maker education in elementary school, it has not been conducted effectively because of the lack of elaborated instructional models and strategies which can facilitate and support learning activities. Based on the procedure of design and development research method, the initial instructional model and strategies were developed through a literature review. After experts’ review and usability test to validate the model and strategies, the results are as follows: the final instructional model includes 10 stages as follows. 1) Empathize, 2) Defining the problem, 3) Tinkering, 4) Making for assembly 5) Designing algorithms and programming with remix 6) Making for creative construction, 7) Debugging&Modifying the computational artifact, 8) Sharing, 9) Reflection, 10) Wrap-up. Also, the instructional strategies consist of 6 general design strategies and 23 detailed guidelines developed to support the sharing of output and processes created through making activities. As a result of pre-post test on computational thinking and maker mindset, it verified that the model and strategies are helpful to conduct maker education using SBC and improve learners’ computational thinking and maker mindset. The theoretical and practical meaning of this study is to develop the optimized instructional model and strategies which can be useful in the field of elementary school context through an empirical approach.
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불소기가 치환된 새로운 티베인 유도체 합성-진통작용 검색 및 친화력 검토를 중심으로
김근재(Keun Jae Kim),김수만(Su Man Kim) 大韓藥學會 1998 약학회지 Vol.42 No.3
5-Methylthebaine was obtained by treating thebaine with n-butyllithium and methylfluorosulfonate. Hetero Diels-Alder reaction of thebaine and 5-methylthebaine with trifluoroacetaldehyde afforded 14-beta-(triflu-oro-2-hydroxyethyl)codeine (2) and 14-beta-(trifluoro-2-hydroxyethyl)-5-methylcodeinone (9). 6-alpha-OH compound (4) was obtained by employing CeCl2 and NaBH4. After synthesized a derivative substituted for 3-OH (5), using boron tribromied, We synthesized a new derivative that make double bond in C-7, C-8 into epoxode (6), (10). Through inspecting an influence on structure-activity and analgetic action, we are going to examine which opiold acceptor has a selectivity.
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