• Archives of Pharmacal Research
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• 제23권2호
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• pp.104-111
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• 2000

Stereochemical isomers with hydroxy groups were synthesized by reacting 2-(dimethoxy-methyl)cyclohexanone with propargylmagnesium bromide. The stereo chemical structures were identified by NMR spectral interpretation and the geometry optimization. To assist the NMR interpretation, geometry optimization based on semi-empirical AM1 and PM3 methods was applied. Throughout this study, the structures of the two isomers were all determined and $^{1}H$ and $^{13}C$ NMR spectra were fully assigned. It was proven that the less polar isomer is an axial alcohol and the more polar one is an equatorial alcohol.

• Current Research on Agriculture and Life Sciences
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• 제5권
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• pp.168-172
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• 1987

광학성체인 isopropylidene glycerols로 부터 mercaptogiycerol을 합성하였다. 1,2-Isopropylideneglycerol을 tosyl화 하고 다시 tosyl group을 thiolacetate로 치환하였다. 염기성 가수분해와 산화에 의해 1,1'-dithiobis-2,3-isopropylidene-2,3-propanediol이 생성되었다. 이 화합물을 mercaptogiycerol 합성을 위해 사용함으로써 1-decenyl lithium으로 cis-S-dec-1'-enyl-2,3-isopropylidene-1-mercapto-2,3-propanediol을 생성하였다. 본 생성물은 plasmalogenase용 thioplasmaloger 기질 조제에 사용된다.

• Bulletin of the Korean Chemical Society
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• 제17권9호
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• pp.786-790
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• 1996

A novel optically active tetraamine ligand possessing four asymmetric centers, N,N'-bis(2(S)-aminopropyl)-1(R),2(R)-trans-1,2-diaminocyclohexane (SRRS-apchxn) and its cobalt(Ⅲ) complexes, [Co(SRRS-apchxn)X2]n+ (X=Cl-, H2O, X2=CO32-) have been synthesized. This ligand has coordinated stereospecifically to the cobalt(Ⅲ) ion to give only the Λ-uns-cis-(SS) isomer. A trans dichloro complex has been obtained via the stereospecific isomerization of Λ-uns-cis-(SS)-[Co(SRRS-apchxn)Cl2]+ to trans-(SS)-[Co(SRRS-apchxn) Cl2]+ in CH3OH-HCl medium. Ligand and complexes have been characterized by electronic absorption, 1H NMR, CD spectra, and also by elemental analysis. It is of interest that this is one of the few CoⅢ(N4)X2 type complex preparations, which produces such an uns-cis isomer with stereospecificity.

• Bulletin of the Korean Chemical Society
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• 제6권6호
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• pp.369-374
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• 1985

A new flexible quadridentate ligand, N,N'-dimethylethylenediamine-N,N'-di-${\alpha}$-propionic acid (dmedpa) has been synthesized, and diammine and ethylenediamine cobalt(III) complexes of dmedpa, $[Co(dmedpa)(NH_3)_2]^+$ and $[Co(dmedpa(en)]^+,$ have been prepared. Only s-cis isomer has been yielede. A known N,N'-dimethylethylediamine-N,N'-diacetic acid (dmedda) has also been prepared. Dichloro cobalt(III) complexes of both dmedda and dmedpa have been prepared. Only the s-cis isomer has been yielded in the $[Co(dmedda)Cl_2]^-$ complex, while only the uns-cis isomer has been obtained for the $[Co(dmedpa)Cl_2]^-$ complex.

• Bulletin of the Korean Chemical Society
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• 제9권6호
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• pp.379-381
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• 1988

Racemic nuciferal(1) and nuciferol(2), the terpenic natural perfumeries, have been synthesized by a simple procedure. The benzylic halide 6; 1-(1-chloroethyl)-4-methylbenzene, was prepared by converting p-tolualdehyde(4) into 1-(p-tolyl)-1-ethanol(5), followed by convertion of 5 into corresponding chloride. The Grignard reagent of 6 was reacted with the bromoacetal 7, 2-(2-bromoethyl)-1,3-dioxolane, to give a crosscoupling product 8, which was hydrolysed to 4-(p-tolyl)-pentanal (9). The Wittig reaction of isopropylide 10 with 9 yielded arcurcumen(11). The stereospecific allylic oxidation of the gem-dimethyl olefin 11 with selenium dioxide afforded a trans-aldehyde, (${\pm}$)-1, which was reduced to corresponding alcohol, (${\pm}$)-2.

• Bulletin of the Korean Chemical Society
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• 제17권5호
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• pp.428-432
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• 1996

Amino acid cobalt(Ⅲ) complexes of 1,3-diminopropane-N,N'-di-α-(β-methyl)-pentanoic acid (H2dpdmp), uns-cis-[Co(dpdmp)(aa)] (aa=glycine, S-alanine, R-aspartic acid, sarcosine) have been prepared from the reaction between the uns-cis-[Co(dpdmp)Cl2]- complex and the corresponding amino acid. In the reaction with the uns-cis-[Co(dpdmp)Cl2]- complex, glycine and S-alanine have yielded both merridional and facial isomers, while R-aspartic acid and sarcosine, only merridional isomers. The stereospecific substitution reaction of R-aspartic acid to racemic uns-cis-[Co(dpdmp)Cl2]- complex has yielded two merridional diastereomers; ΛR-uns-cis- and ΛR-uns-cis-[Co(dpdmp)(R-asp)]. It is of interest to note that this is one of the few CoⅢ(ONNO)(aa) type complex preparations, which gives only one isomer with stereospecificity. On the other hand, two merridional products obtained from the reaction of sarcosine with racemic uns-cis-[Co(dpdmp)Cl2]- are turned out to be mixtures of optical isomers.

• Bulletin of the Korean Chemical Society
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• 제7권6호
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• pp.472-477
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• 1986

The reaction of (E)- or (Z)-1-alkenylmercuric chlorides with acrylic acid derivatives in the presence of 10 mol% of lithium trichloropalladate ($LiPdCl_3$) and an equimolar amount of cupric chloride, as a reoxidant for the palladium, in acetonitrile at room temperature gave the corresponding (E,E)- or (E,Z)-2,4-dienoic acid derivatives stereospecifically in moderate to good yields. The reaction of (E)- or (Z)-3-chloromercuripropenoic acid with olefins under the reaction condintion described above similarly gave good yields of (E,E)- or (Z,E)-2,4-dienoic acids stereospecifically. A side reaction, the homocoupling of alkenylmercuric chlorides, could be minimized by employing the condition described above. However, in the reaction of 3-chloromercuripropenoic acid with olefins under the present condition, the homocoupled side reaction product was not produced.

• Bulletin of the Korean Chemical Society
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• 제5권5호
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• pp.191-193
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• 1984

6, 6-Diiodopenicillanic acid was prepared from 6-aminopenicillanic acid using iodine-sodium iodide systems in good yield (60%). Enolates derived from 6-chloro-6-iodo-, 6,6-diiodo-penicillanate have been generated in situ by a metal-halogen exchange process at -$78^{\circ}C$ using methylmangnesium iodide and reacted with acetaldehyde to yield aldols. As the size of remaining halogen atom increases, the proportion of ${\beta}$-face attack was increased. In the case of 6,6-diiodopenicillanate, only ${\beta}$-face attack was observed yielding a single isomer (6S, 8R).

• Bulletin of the Korean Chemical Society
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• 제5권6호
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• pp.237-240
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• 1984

2,2'-Diaminobiphenyl platinum (II) complexes of optically active trans-1,2-diaminocyclohexane and 1,2-diaminopropane, [Pt(S,S-chxn)(dabp)]Cl2, [Pt(R,R-chxn)(dabp)]$C_{12}$, [Pt(S-pn)(dabp)]$C_{l2}$, and [Pt(R-pn)(dabp)]Cl2, where S,S-chxn and R,R-chxn are, respectively, S and R isomers of trans-1,2-diaminocyclohexane, and S-pn and R-pn are, respectively, S and R isomers of 1,2-diaminopropane, and dabp the 2,2'-diaminobipheny, have been prepared. The dabp ligand has been found to take the $=delta$ conformation in the S,S-chxn and S-pn platinum (II) complexes, while it takes the $\lambda$ conformation in the R,R-chxn and R-pn platinum (II) complexes.

• 대한화학회지
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• 제41권9호
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• pp.465-470
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• 1997

입체특이성 반응을 나타내는 키랄성 다섯자리 리간드, 1,9-bis(S)-prolyl-1,9-dioxo-2,5,8-triaza-nonane(S,S-prochen)를 S-proline과 diethylenetriamine (dien)으로부터 합성하여 $^{13}C-NMR$스펙트럼으로 확인하고, $CoCl_2{\cdot}6H_2O$와 반응시켜 적자색의 착물인 $[Co(SS-prodien)H_2O]ClO_4$ 를 합성하였다. 원소분석, 전자흡수스펙트럼, $^{13}C-NMR$스펙트럼 자료에 따라 S,S-prodian은 5자리로 배위되면서 중심의 dien부분은 fac형태로 결합하고, 한자리 리간드인 $H_2O$는 dien에 있는 2차질소원자에 대하여 cis 위치에 존재하는 ${\alpha}{\beta}$ (ffm)-형임을 알게되었다. 또한 CD스펙트럼에 따라 킬레이트된 리가드는 입체선택적으로 배위되어 ${\Lambda}$-${\alpha}{\beta}$ (ffm)-$[Co(SS-prodien)H_2O]^+$의 절대구조를 갖는다고 생각하였다.