• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.2038-2040
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• 2005

• Bulletin of the Korean Chemical Society
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• 제16권1호
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• pp.12-16
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• 1995

The diastereoselectivity of addition reaction of crotylmetal reagents to cobalt-complexed acetylenic aldehydes and metal-free aldehydes was examined. The anti-diastereomer was the predominant product when the crotyl metallics were Cr, Sn, and Zr. In THF, the uncomplexed aldehydes normally gave higher anti-diastereoselectivity. However, the cobalt-complex of silicon-substituted propynals with three bulky substituents produced increased proportions of syn-diastereomer. In DMF, the selectivity shifted towards syn-isomer except in the case of dimethylphenylsilyl substituent. When tributylstannane was used in the presence of BF3 etherate, moderate syn- selectivity was observed with uncomplexed aldehydes, but only decomposed products from complexed aldehydes.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.441-442
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• 2004

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.797-802
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• 2009

Potential of acetates and related compounds in glacial acetic acid as a catalyst for aldol-type condensation reactions was examined. Reactions of cycloalkanones or selected heteroaromatics with aldehydes in presence of 10 mol% of various acetates in acetic acid afforded ${\alpha},{\alpha}$'-bis(substituted-benzylidene)cycloalkanones and substituted-benzylidene-mackinazolinones, respectively, in good yields. Among the compounds tested, ammonium acetate is the best and effective especially towards the reactions of mackinazolinone and aliphatic aldehydes to afford 6-alkylidenemackinazolinones.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.219-224
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• 2011

The new MPV type reagent, Al-trifluoromethanesulfonyldiisobutylalane ($DIBAO_3SCF_3$), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined, and compared its reactivity with that of Al-methanesulfonyldiisobutylalane ($DIBAO_3SCH_3$) in order to understand the fluorine-substituent effect on its reactivity. In general, the reactivity of $DIBAO_3SCF_3$ appears to be much higher than that of $DIBAO_3SCH_3$, apparently due to the acidity increase by the electron-withdrawing fluorine-substituent. The reagent reduced aldehydes and ketones readily, but showed a perfect selectivity in the reduction of $\alpha,\beta$-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagent achieved the regioselective cleavage of phenyl- or/and alkyl-substituted epoxides to the less substituted alcohols in a perfect regioselectivity. Moreover, the reagent also showed an high stereoselectivity in the reduction of substituted cycloalkanones to produce the thermodynamically more stable alcohol epimers exclusively.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.723-728
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• 1998

The chemical behaviours of 4-methyl-2-oxo-2H-benzopyran-7-yl oxoacetyl hydrazine (2) towards some different reagents such as anhydride compounds, aromatic aldehydes, carb on disulphide, and nitrous acid yielded the corresponding pathalazine derivatives (3, 4, 5), hydrazone derivative (6), 1,3,4-oxadiazole derivative (7, 8, 9) and acid azide (10) respectively. Treatmen of 10 with absolute alcohols, amines and ethyl amino acid ester gave the corresponding carbamate derivative (11), substituted urea derivative (12) and ethyl substituted alkyl acetate (13) respectively. The biological activity of some synthesized compounds was evaluated.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1739-1745
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• 2007

A new methodology for the preparation of pyranochromenes was developed starting from substituted trihydroxybenzenes. This methodology was applied successfully to the total synthesis of biologically interesting compounds, clusiaphenone A, octandrenolone, O-methyloctandrenolone, trans-3''',4'''-dihydro- 3''',4'''-dihydroxy-O-methyloctandrenolone, trans-3'',4''-dihydro-3'',4''-dihydroxy-O-methyloctandrenolone, flemiculosin, laxichalcone, and racemic 3-deoxy-Ms-II.

• 대한화학회지
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• 제42권4호
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• pp.449-453
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• 1998

6-Chloro-2-hydrazinoquinoxaline 4-oxide(11)와 ethyl chloroglyoxylate를 반응시켜 분자내 고리화반응에 의한 ethyl 8-chloro-4H-1,3,4-oxadiazino[5,6-b]quinoxaline-2-carboxylate(12)를 합성하였다. 화합물 12를 hydrazine hydrate와 반응시켜 $C_2$-hydrazinocarbonyl 유도체 13이 합성되었는데, 이것을 치환 벤즈알데히드류 및 헤테로아릴 알데히드류와 반응시켜 8-chloro-2-(substituted benzylidenehydrazinocarbonyl)-4H-1,3,4-oxadiazino[5,6-b]quinoxaline류(14) 및 8-chloro-2-[(2-substituted methylidene)hydrazinocarbonyl]-4H-1,3,4-oxadiazino[5,6-b]quinoxaline류(15)를 각각 합성하였다.

• 대한화학회지
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• 제54권4호
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• pp.411-413
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• 2010

HPA-phosphomolybdic acid 촉매 하에서, 아릴히드라진과 알데히드/케톤을 반응시켜서 치환기를 가지고 있는 indole 화합물을 효율적으로 합성할 수 있는 친환경적인 합성 방법을 개발하였으며, 이때 촉매는 독성이 없으며, 회수하여 재 사용할 수 있다.

• 대한화학회지
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• 제56권3호
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• pp.328-333
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• 2012

A simple, convenient and practical green synthetic protocol for sodium bisulfite catalyzed multicomponent reaction of ethyl acetoacetate, hydrazine hydrate, malononitrile, and various aldehydes for the synthesis of 6-amino-4-phenyl-3-methyl-2,4-ihydropyrano[2,3-c]pyrazole-5-carbonitriles using ultrasound irradiations in solvent free condition. This method provides the advantage of operational simplicity, shorter reaction time and excellent yields making the protocol environment friendly and economically lucrative.