• Bulletin of the Korean Chemical Society
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• v.11 no.3
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• pp.241-244
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• 1990

The photochemistry of 1-Methyl-2-cyclohexenyl aryl ketones (phenyl ketone 7a, p-toluyl ketone 7b, biphenyl ketone 7c and -naphthyl ketone 7d) is reported. The aryl ketone 7a, 7b and 7c undergo photo-racemization with efficiencies of 0.75, 0.79 and 0.76 respectively on direct irradiation. Direct irradiation of the ketone 7d, however, undergoes 1,3-shift with an efficiency of 0.02. Triplet states are responsible for the racemizations and singlet state is responsible for 1,3-shift as in general. The ketone 7a, 7b and 7c are good example of a few ${\beta},{\gamma}$-unsaturated ketones which undergo efficient intersystem crossing on direct irradiation.

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.644-649
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• 1991

The approximate rates and stoichiometry of the reaction of excess lithium tris(dibutylamino)aluminum hydride (LT-DBA) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, $0^{\circ}C$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of LTDBA was also compared with those of the parent lithium aluminum hydride and the alkoxy derivatives. The reagent appears to be much milder than the parent reagent, but stronger than lithium tri-t-butoxyaluminohydride in reducing strength. LTDBA shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and amides readily. In addition to that, ${\alpha},{\beta}$-unsaturated aldehyde is reduced to ${\alpha},{\beta}$-unsaturated alcohol. Quinones are reduced to the corresponding diols without evolution of hydrogen. Tertiary amides and aromatic nitriles are converted to aldehydes with a limiting amount of LTDBA. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively, without hydrogen evolution.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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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.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.313-318
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• 1987

The approximate rate and stoichiometry of the reaction of excess Thexylbromoborane-methyl sulfide, $ThxBHBr{\cdot}SMe_2,$ with selected organic compounds containing representative functional groups under standardized conditions (methylene chloride, $0^{\circ}C)$ were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The selectivity of the reagent was also compared to the selectivity of thexylchloroborane-methyl sulfide. Thexylbromoborane appears to be a much milder and hence more selective reducing agent than thexylchloroborane. The reagent tolerates many organic functionalities. Thus, the reagent shows very little reactivity or no reactivity toward acid chlorides, esters, epoxides, amides, nitro compounds including simple olefins. However, this reagent can reduce aldehydes, ketones, carboxylic acids, nitriles, and sulfoxides. Especially the reagent reduces carboxylic acids including ${\alpha},{\beta}$ -unsaturated ones and nitriles to the corresponding aldehydes. In addition to that, thexylbromoborane shows good stereoselectivity toward cyclic ketones, much better than the chloro-derivative.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.22-28
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• 1998

Twenty six derivatives of bis-aromatic ${\alpha},{\beta}$-unsaturated ketones as substrate(S) were synthesized and their fungicidal activities in vivo against rice blast(Pyricularia oryzae), tomato leaf blight(Phytophtora infestans) and barley powdery mildew(Erysiphe graminis) were examined. The quantitative structure-activity relationship(QSAR) between the fungicidal activities($pI_{50}$) and a physicochemical parameters of substitued($R_{2}$) phenyl backbone group in 2-thienyl and 2-furyl substituents were analyzed with regression equations. The activities of substituted($R_{2}$) phenyl backbone in 2-thienyl substituents, $1{\sim}10$ would depend largely on the resonance(R>0), molecular refractivity($M_{R}<0$) and optimal length of substituent(($L_{1})opt.=5.50{\AA}$). Whereas, in case of 2-furyl substituents, $10{\sim}26$ optimal molar attraction constant ($F_{opt}=0.49{\sim}l.11$), optimal steric($Es_{opt}=1.78$) constant and indicator variables(Io & Ip) for position of substituents. The fungicidal activity relationship of 2-thienyl substituents against Pyricularia oryzae and Phytophtora infestans have been a reciprocal proportioned.

• Archives of Pharmacal Research
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• v.12 no.2
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• pp.135-137
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• 1989

A convenient route is reported for the synthesis of certain series of 4H-thieno[2,3-b][1]benzothiopyran-4-ones, carrying various substituents at position 2 such as arylazomethines (7,8), thiazolidin-4-ones (9-13), ${\alpha},\;{\beta}-unsaturated$ ketones (16,17), 2-pyridones (19-23), tetrahydrothiophen-4-ones (24,28), and nitroalkenes (29,30), as potential schistosomicidal or antihistaminic agents.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.142-146
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• 1990

Reaction of ethyl 4-chloro-2-phenylpyrimidine-4-carboxylate (4) with 5-chloro-2-methylthiophenol or 3-aryl-4-phenyl-1, 2, 4-triazole-5 thiol yielded the corresponding thioethers (5) and (8a, b), respectively. Careful alkaline hydrolysis of (5) yielded the corresponding carboxylic acid (6). Reaction of (4) with p-aminoacetophenone yielded compound (10) which was reacted with certain aromatic aldehyde to afford the$\alpha,\beta$-unsaturated ketones (11a-d). Condensation of (11a-d) with malononitrile or phenylhydrazine yielded the 2-amino-3-cyanopyridines (12a-f) or the 2-pyrazolines (13a, b) respectively. Seven representative compounds were tested for their in vitro antimicrobial activity against some pathogenic micro-organisms, some of them were proved to be active.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1194-1201
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• 2004

Michael addition of certain nucleophiles on ${\alpha}$ , ${\beta}$-unsaturated ketones 1 led to the formation of adducts 2-7 as well as the reaction of arylidene derivatives with secondary amines afforded the amino compounds 9 and 11. Also, dialkylmalonates were treated with ${\alpha}$-cyano cinnamide to afford 13. On the other hand, double Michael cycloaddition of ethylcyanoacetate or tetrachlorophthalic anhydride to the suitable divinylketone were synthesized to produce 15-17. Selected compounds (13 and 6) were screened for muscle relaxant, anticonvulsant, and sedative activities using established pharmacological models. Their activities were compared with that of phenobarbital sodium taken as standard. Compound 6 was the most potent muscle relaxant while compounds 13a and 13c offered the highest anticonvulsant activity. Meanwhile compound 13c showed the highest potentiation of phenobarbital induced sleep in mice.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.458-461
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• 1995

+To prove uniqueness of allylic alcohol formation from ${\alpha},{\beta}-unsaturated$ ketones by mammal enzymes, a metabolic pattern of dehydroparadols, non-pungent synthetic analogs of shogaol by Aspergillus niger was examined. Two biotransformation products of a dehydroparadol, 1-(4hydroxy-3-methoxyphenyl)-non-1-en-3-one were accumulated in the culture broth of A. niger. They were characterized as 1-(4-hydroxy-3-methoxyphenyl)-non-1-en-9-01-3-one and 1-(4-hydroxy-3-methoxyphenyl)-nonan-9-o1-3-one by UV, NMR and mass spectroscopic analyses. Accumulation of allylic alcohol metabolites was not observed.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2961-2966
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• 2010

Reduction of carbonyl compounds such as aldehydes, ketones, $\alpha,\beta$-unsaturated enals and enones, $\alpha$-diketones and acyloins was carried out readily with $NaBH_3CN$ in the presence of wet $SiO_2$ as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - $80^{\circ}C$) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction of conjugated carbonyl compounds took place in a perfect selectivity without any side product formation.