• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2776-2782
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• 2010

Newly developed Horner-Wadsworth-Emmons (HWE) reagents 5 having triphenylphosphorane ylide subunits readily condensed with various carbonyl compounds under mild reaction conditions to afford $\beta,\gamma$-unsaturated $\alpha$-keto triphenylphorane ylides in good to excellent yields, which were hydrogenated over Pd-C (10%)/$H_2$ (1 atm) to give the corresponding $\alpha$-keto triphenylphorane ylides in quasi-quantitative yields. These triphenyphosphorane ylides have been utilized as the precursors to $\alpha$-keto amide/ester and vicinal tricarbonyl units in Wasserman's synthetic protocols, and have previously been prepared only from carboxylic acids/acid chlorides. Our new approaches provide excellent alternatives for the synthesis of triphenylphosphorane ylide precursors to $\alpha$-keto amide/ester and vicinal tricarbonyl units directly from carbonyl compounds in good to excellent yields.

• Korean Journal of Pharmacognosy
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• v.17 no.2
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• pp.178-183
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• 1986

It was our working hypothesis that introduction of 11-keto groups to 12-oleanene/ursene series of triterpenoids should endow them with corticoid-like activities, since pharmacological actions of glycyrrhetinic acid (GA) are known to be caused by inhibition on $corticoid-{\delta}^4-reductase$. 11-Keto-triterpenoids derived artificially in these studies, such as 11, 19-diketo-18, 19-secoursolic acid methyl ester(I), $11-keto-{\beta}-boswellic$ acid derivatives (IIa-IIc), 11-Keto-presenegenin dimethyl ester (III), II-keto-oleanolic acid derivatives (IVa-IVd) and 11-keto-hederagenin (V) possess the fundamental functions of ${\alpha},\;{\beta}-unsaturated$ ketone on C-11 and hydroxyl group on C-3, as like GA (VI). Additionally, they involve the carboxyl groups on rings A (II, III), D (I, III, IV, V) and E (VI), and the hydroxyl groups on rings A (III, V) and C (III). All the compounds competitively inhibited $corticoid-5{\beta}-reductase$, and the highest inhibitory potency appeared in I. All of them except $3,\;11-diketo-{\beta}-boswellic$ acid methyl ester (IIc) were more effective about five times to twice than GA. On carrageenin-induced edema test, compounds I and IVa-IVd showed anti-inflammatory activities, but III enhanced rather edema. Structure-activity relations were found in the aspects of hydrophilicity of ring A and hydrophobicity of rings C/D. The more they were hydrophilic in ring A and hydrophobic in rings C/D, the more they inhibited the enzyme. And the more they were hydrophobic in rings C/D, the more they exhibited antiiflammatory activities. However, the increased hydrophilicity in ring A resulted in increasing edema, probably due to a nonspecific inhibition on $aldosterone-5{\beta}-reductase$.

• Bulletin of the Korean Chemical Society
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• v.22 no.3
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• pp.327-329
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• 2001

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2953-2958
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• 2013

A noble phenylsulfonyl reagent 8 having ${\alpha}$-oxo (cyanomethylene)triphenylphosphorane ylide subunit readily condensed with various alkyl halides under basic conditions to afford ${\beta}$-alkyl-${\alpha}$-oxo-${\beta}$-phenylsulfonyl (cyanomethylene)triphenylphosphorane ylides 9 in excellent yields. These sulfonyl ylides 9 were then reductively desulfonylated with $Na(Hg)/Na_2HPO_4$ in the presence of methanol to provide ${\alpha}$-keto (cyanomethylene)-triphenylphosphorane ylides 2' in good to excellent yields. Our new synthetic approach offers an expeditious access to various ${\alpha}$-keto (cyanomethylene)triphenylphosphorane ylides from alkyl halides utilizing a new phenylsulfonyl reagent as the key reagent under mild reaction conditions in good overall yields.

• Archives of Pharmacal Research
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• v.9 no.4
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• pp.237-242
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• 1986

The Synthesis of E, E, E-12-fluorofarnesol and E, Z-6-fluorofarnesol which are key intermediates for the study of biosynthesis of some sesquiterpenes, is described. E, E-Farnesyl acetate is treated with selenium dioxide to give E, E, E-12-hydroxy farnesyl acetate, whih is transformed by DAST into E, E, E-12-hydroxy farnesyl acetate, which is transformed by DAST into E, E, E,-12-fluorofarnesylacetate. The latter compound is hydrolyzed to E, E, E,-12-fluorofarnesol. The reformatsky reaction of 6-methyl-5-hepten-2-one with ethyl bromofluoroacetate affords ethyl 2-fluoro-3-hydroxy-3, 7 dimethyl-6-octanoate. This ester is acetylated and eliminated to give ethyl (Z)-2-fluoro-3, 7-dimethylocta-2, 6-dienoate, which is transformed to allyl bromide via allylic alcohol. The allyl bromide is treated with dianion of methyl acetate to give-keto ester. The $\beta$-keto ester is converted to diethyl phosphoryloxy compound. The conjugate addition of lithium dimethylcuprate to the latter compound gives fluoro ester, which is treated with DIBAL to afford E, Z-6-fluorofarnesol.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.190.2-191
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• 2001

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.549-550
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• 2005

• Journal of the Korean Chemical Society
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• v.38 no.12
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• pp.908-914
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• 1994

6a-Hydroxy- and 6a-methoxy-derivatives (1∼6) of octahydro-2,3-dioxo-cyclopenta[b]-pyrrole-3a-carboxylate were synthesized from oxalylation of enamine A, which was prepared from condensation of five-membered cyclic ${\beta}$-keto ester and phenylalkylamine, followed by addition of water or methanol. The formation of heterocyclic ring was assumed to occur by the way of unstable N-acyliminium (B). Stable adduct C (1∼6) was obtained from nucleophilic addition to the endo-ene type pyrrolinium B.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.397-401
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• 1994

Bioreduction with active dried baker's yeast proceeded smoothly in n-hexane, pentane or petroleum ether as an organic solvent system. Ethyl(1) and octyl 3-oxohexanoate(2) were reduced to $({\underline{R}})-ethyl(3)$ and $({\underline{S}})-octyl$ 3-hyroxy-hexanoate(4) with high enantiomeric excess, respectively.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.21-21
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• 1992

녹용은 한방에서 신경조절 약화, 신체발육부진, 허약체질 등에 사용되는 강장제로서 인삼과 더불어 중요한 약재 중의 하나이지만 아직까지 유효 성분이 밝혀져 있지 않다. 알려진 녹용의 성분으로 collagen, acid mucopolysaccharide, 중성지질, 당지질, ganglioside, 인지질, proteolipid, prostaglandins, estrone, estradiol, cholesterol, its ester, 7-keto-cholesterol, 7$\alpha$-hydroxycholesterol , 7$\beta$-hydroxycholesterol , p-hydroxy-benzaldehyde, uracil, uridine, hypoxanthine, nicotinic acid, creatinine urea 등이 보고되었다. 이와 같은 성분들은 동물조직에서 공통적으로 발견되는 것들로서 녹용의 특이성분이라 부르기 어렵다. 그러나 uracil, uridine, hypoxanthine과 같은 핵산염기 관련 성분은 녹용에 비교적 함량이 많고, 이중에서 hypoxanthine은 monoamine oxidase-B에 대한 저해작용이 있으므로 주목할 필요성이 있다.