Journal of Synthetic Organic Chemistry, Japan
Online ISSN : 1883-6526
Print ISSN : 0037-9980
ISSN-L : 0037-9980
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Volume 49, Issue 2
Displaying 1-9 of 9 articles from this issue
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  • Synthetic Studies on Optically Active and Biologically Active Compounds
    Shiro TERASHIMA
    1991Volume 49Issue 2 Pages 98-109
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.98
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    Based on the consideration that biologically active chiral compounds should be prepared in optically active forms which show desired biological activities, the compounds not only exhibiting interesting biological activities but also bearing intriguing structures were selected as synthetic targets and their efficient syntheses were studied by employing optical resolution, asymmetric synthesis and chemical transformation. Thus, efficient syntheses of the anticancer agents such as anthracyclines, nogalamycins, and sesbanimides were accomplished in optically active forms. Syntheses of optically active quinocarcin and fredericamycin A showing pronounced anticancer activities were also studied. A number of efficient synthetic routes to the optically active key intermediates of antibacterial carbapenem antibiotics and antihypertensive peptide-like renin inhibitors were successfully explored.
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  • Stereochemical Control in Microbial Reduction
    Kaoru NAKAMURA, Atsuyoshi OHNO
    1991Volume 49Issue 2 Pages 110-117
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.110
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    Stereochemistry in the reduction of ketones with microbes is controlled by two methods. Immobilization of the microbe and utilization of the specific inhibitor are effective for controlling the course of the reduction The reduction with immobilized bakers' yeast in polyurethane gives D-alcohols while that immobilized in magnesium alginate gives L-alcohols. As an inhibitor, methyl vinyl ketone is effective for obtaining D-alcohols whereas the reduction in the presence of ethyl chloroacetate affords L-alcohols. Thus both enantiomers of chiral alcohols are prepared in high enantiomeric excesses by a single microbe. Diastereoselectivities in the reduction of 2-alkyl-3-oxobutanoate with bakers' yeast are also controlled.
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  • Versatile Chiral Synthons for 2-Amino Alcohols
    Tadao ISHIZUKA, Takehisa KUNIEDA
    1991Volume 49Issue 2 Pages 118-127
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.118
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    The 2-oxazolone heterocycle is proved of synthetic potential as a building block for 2-amino alcohol structures, which are found in a substantial number of bioactive compounds such as enzyme inhibitors, antibiotics and sympathomimetic amines. The synthetic strategy consists of the following steps : (1) the diastereoselective introductions of easily replaceable groups (X, Y) to the olefinic moiety of the 2-oxazolone, (2) stereospecific and stepwise substitution of X and Y with appropriate groups and (3) the opening of the 2-oxazolidone ring system under mild condition.
    Methoxybromination (Br2/MeC (OMe) 3) and methoxyselenylation (PhSeCl/MeOH) of 3- (2-exo-alkoxy apocamphanecarbonyl) -2-oxazolone proceed smoothly to result in highly stereoselective formation of chiral synthons for 2-amino alcohols, but with opposite π-facial selectivity Effective conversion of these adducts to biologically significant 2-amino alcohols such as statine and β-hydroxyglutamic acid is described.
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  • Development of Highly Selective Methods for Introduction of Carbon Substituents to Nitrogen Heterocycles by Means of Organotin Reagents and Application to Synthesis of Nitrogen Polycycles
    Ryohei YAMAGUCHI
    1991Volume 49Issue 2 Pages 128-137
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.128
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    Highly effective methods for introduction of several kinds of carbon substituents have been developed by means of organotin reagents. Allyl-, alkynyl-, allenyl-, and benzyltin reagents readily react with N-acylated nitrogen heteroaromatics and cyclic imines in a highly chemo- and regioselective manner. Functionalized acylating agents, such as α, β, γ, δ-unsaturated, α, β-unsaturated, and β-halogenated acyl chlorides can be utilized in the reactions and the subsequent intramolecular cyclizations afford nitrogen polycycles related to protoberberine, yohimbane, and indolizidine alkaloids.
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  • Living Polymerization of Substituted Acetylenes by Transition Metal Catalysts
    Toshio MASUDA
    1991Volume 49Issue 2 Pages 138-146
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.138
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    Catalysts composed of MoOCl4 (or MoCl5), nBu4Sn, and ethanol effect living polymerization of 1-chloro-1- octyne; i, e., this polymerization provides a polymer with narrow molecular weight distribution (MWD) (Mw/ Mn 1.1-1.3), whose molecular weight increases in direct proportion to conversion. These Mo-based three-component catalysts polymerize also o-Me3Si-, o-CF3-, and p- nBu- o, o, m, m-F4-phenylacetylenes in a living fashion irrespective of the electronic effect of ortho-substituent (Mw/Mn 1.05-1.2). In the presence of MoOCl4-nBu4Sn-EtOH, tert-butylacetylene yields a stereoregular living polymer (cis 97%, Mw/ Mn1. 1). Reaction of MoOCl4 (or MoCl5) with nBu4Sn affords a metal carbene, and ethanol stabilizes it by replacing chlorine ligand with ethoxy group, which will eventually lead to living polymerization. Living polymerization of substituted acetylenes by other catalysts is also mentioned.
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  • Synthesis of Enkephalin Analogs with Ability to Recognize Discriminatively the Opioid Receptor Subtypes
    Yasuyuki SHIMOHIGASHI
    1991Volume 49Issue 2 Pages 147-157
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.147
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    Three different types of design strategies have been developed to synthesize the enkephalin analogs that bind to the opioid receptor subtypes selectively and specifically. They include the methods of incorporation of structurally constrained amino acids, dimerization of peptide backbone, and incorporation of activated thiol groups for covalent attachment to the receptor. With detailed molecular pharmacological examinations, several enkephalin analogs have been demonstrated as ligands of distinct characteristics for receptor selections.
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  • [title in Japanese]
    Teruo YASUI
    1991Volume 49Issue 2 Pages 158-162
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.158
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  • Geraniol (2-trans-3, 7-Dimethyl-2, 6-octadueb-1-ol)
    Goro ASANUMA
    1991Volume 49Issue 2 Pages 163-164
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.163
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  • [title in Japanese]
    [in Japanese], [in Japanese], [in Japanese]
    1991Volume 49Issue 2 Pages 165
    Published: February 01, 1991
    Released on J-STAGE: November 16, 2009
    DOIhttps://doi.org/10.5059/yukigoseikyokaishi.49.165
    JOURNAL FREE ACCESS
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