Showing papers in "Journal of Synthetic Organic Chemistry Japan in 1980"
TL;DR: A large number of compounds have been synthesized, laying stress on S-benzyl thiol carbamates, including S-4-chlorobenzyl N, N-diethylthiol carbamate (Benthiocarb).
Abstract: In 1964, slender-spikerush was received major attention as weeds in paddy field because of revelation resistance to the effect of herbicide hithertofore in use.Authors aimed at search of herbicide for controlling slender-spikerush.A large number of compounds have synthesized, laying stress on S-benzyl thiolcarbamates.These compounds were evaluated for especially slender-spikerush in addition to barnyard grass and broad leaf plant as usual.From the results, S-4-chlorobenzyl N, N-diethylthiolcarbamate (Benthiocarb) was selected as a compound having most effectiveness.On the other hand, the preparation process of carbonyl sulfide was established and has been applied to the synthesis of Benthiocarb.By this process, Benthiocarb was obtained with high-purity and high-yield.
19 citations
TL;DR: Recent advances of the chemistry of aliphatic nitro compounds are reviewed in this article, in which the following items are covered: Preparation and reaction of alphatic compounds.
Abstract: Recent advances of the chemistry of aliphatic nitro compounds are reviewed, in which the following items are covered. 1) Preparation of aliphatic nitro compounds. 2) Reaction of aliphatic nitro compounds which includes substitution and elimination reaction of the nitro group, conversion of the nitro group to the carbonyl or amino group and organic synthesis using nitroolefins.
16 citations
TL;DR: Alkaline condensation of 3-acetyltropolone (1) with benzaldehydes gave 3-cinnamoyltropolsones (2 a-d), which were cyclized with concentrated orthophosphoric acid to afford 2-aryl-2, 3, 4, 9-tetra-hydrocyclohepta [b] pyran-4, 9diones (3a-d) as mentioned in this paper.
Abstract: Alkaline condensation of 3-acetyltropolone (1) with benzaldehydes gave 3-cinnamoyltropolones (2 a-d), which were cyclized with concentrated orthophosphoric acid to afford 2-aryl-2, 3, 4, 9-tetra-hydrocyclohepta [b] pyran-4, 9-diones (3a-d) and oxidized with selenium dioxide to give 2-aryl-4, 9- dihydrocyclohepta [b] pyran-4, 9-diones (4a-d).
15 citations
13 citations
TL;DR: The recent progress of carbon-carbon bond formation via organotin compounds is described in this article, which can be divided roughly into two categories, substitution of organic halides and addition of carbonyl compounds.
Abstract: Recent progress of carbon-carbon bond formation via organotin compounds is described. These reactions can be devided roughly into two categories, that is, substitution of organic halides and addition of carbonyl compounds. Among the organotin compounds, allyl-, vinyl-, ethynyl-, and phenyl-trialkyltin are promising reagents.
12 citations
11 citations
TL;DR: In this paper, the synthesis and synthetic approaches of thienamycin and its related compounds are summarized according to the manner for the formation of carbapenem and carbapensam ring systems.
Abstract: Thienamycin, an exceptionally potent, broad spectrum β-lactam antibiotic, possesses a novel 1-carbapen-2-em structure. Total syntheses and synthetic approaches of thienamycin and its related compounds, which have been published before early in June of 1980, are summarized according to the manner for the formation of carbapenem and carbapenam ring systems.
10 citations
9 citations
TL;DR: In this article, the synthesis of C-nucleosides starting with non-carbohydrate precursors is reviewed and most entries described in this paper utilize 2+4 or 3+4 type cycloaddition reaction in the key step, which allows strict stereochemical control of the four chiral centers.
Abstract: Synthesis of C-nucleosides starting with non-carbohydrate precursors is reviewed. Most entries described herein utilize 2+4- or 3+4-type cycloaddition reaction in the key step, which allows strict stereochemical control of the four chiral centers.
8 citations
TL;DR: In this article, the aluminum Lewis acid center serves to bind the substrate and subsequently the base directly attached to aluminum is excited by the coordination and attacks the substrate in the following rate and product-determining step.
Abstract: Synthetically useful reactions mediated by reagents containing aluminum as a key atom are disclosed. The reagents perform combined acid-base attack on substrates with less activation energies. The aluminum Lewis acid center serves to bind the substrate and subsequently the base directly attached to aluminum is excited by the coordination and attacks the substrate in the following rate-and product-determining step. Supports of this idea as well as extensions are described.
8 citations
TL;DR: The synthetic utility of the Polonovski reaction has recently been widely explored as mentioned in this paper, including its use in dealkylation of tertiary amines and enamines, it can also be used in the syntheses of a Mannich reagent and many indole alkaloids.
Abstract: The synthetic utility of the Polonovski reaction has recently been widely explored. Besides classical use in dealkylation of tertiary amines and in the preparation of enamines, it can also be used in the syntheses of a Mannich reagent and many indole alkaloids. Success in the syntheses of vinblastine and related compounds is one of the most important developments. The present review summarizes the synthetic applications of this reaction.
TL;DR: In this paper, nine 3-cinnamoyltropolones were oxidized with hydrogen peroxide in the presence of alkali to afford 2-benzylidene-3, 8-dihydro-2H-cyclohepta [b] furan- 3, 8 -diones 4 a-i which have an aurone-like structure.
Abstract: Nine 3-cinnamoyltropolones 1 a-i were oxidized with hydrogen peroxide in the presence of alkali to afford 2-benzylidene-3, 8-dihydro-2H-cyclohepta [b] furan- 3, 8 -diones 4 a-i, which have an aurone-like structure. In some cases, methoxy-substituted benzaldehydes and/or phenols were isolated, besides 4.
TL;DR: The mesophase is a kind of liquid crystal state, which often determines the structure, orientation, and crystalinity of graphite-like crystallinite and of the semicoke as mentioned in this paper.
Abstract: Carbonization and graphitization reactions of carbonaceous molecules leading to the various carbon material of important application are reviewed from the viewpoint of physical organic chemistry in spite of their complexity and physical nature. The carbonization reactions consist of polymeric condensation and solidification. Some systems produce the mesophase (intermediate phase), a kind of liquid crystal state, which often determines the structure, the orientation, and crystalinity of graphite-like crystallinite and of the semicoke. The mesophase is reviewed rather extensively as for its formation, structure, and properties.Analyses of the reaction scheme reveal the factors influencing the formation of mesophase and provides the some ideas for the design of carbonization. Catalytic and cocarbonization processes are introduced based on such analyses to modify the reaction for the production of desirable carbon material.Chemical modification of heavy carbonaceous material such as pitch and coals is overviewed in relation with carbonaceous resource problems.
TL;DR: The carbon-silicon bond in organopentafluorosilicates is readily cleaved by electrophiles or oxidizing agents such as halogens, NBS, CuX2, MCPBA, and TCNE and various functional groups are selectively introduced to the carbon atom which has been attached to the silicon atom as mentioned in this paper.
Abstract: Preparative methods, properties, and reactions of organofluorosilicates, M2 [RSiF5], have been reviewed. Since organopentafluorosilicates contain a doubly-negatively charged hexacoordinate silicon atom, their reactivities are quite different from those of neutral tetracoordinate organosilanes. The carbon-silicon bond in organopentafluorosilicates is readily cleaved by electrophiles or oxidizing agents such as halogens, NBS, CuX2, MCPBA, and TCNE, and various functional groups are selectively introduced to the carbon atom which has been attached to the silicon atom. The organic group in the silicate can also be transferred to other metals such as Cu (I), Ag (I), Pd (II), Hg (I), Hg (II), Tl (III), and Bi (III). The transmetalation provides various types of carbon-carbon bond forming reactions.
TL;DR: A review of recent progress in the prostaglandin field can be found in this article, where the authors discuss the synthetic studies of endoperoxides, thromboxanes, prostacyclins and leukotrienes.
Abstract: This review, including two parts, deals with recent progress in the prostaglandin field. The first part is concerned with the synthetic studies of endoperoxides, thromboxanes, prostacyclins and leukotrienes. The second describes briefly the biological properties of various stable synthetic analogs.
TL;DR: A survey on the current aspect of glycosylation reaction can be found in this article, which is in turn described using utilization of glycoly halide derivatives, of 1, 2-orthoester sugar derivatives and of 1-O-acyl sugar derivatives.
Abstract: The present article involves a survey on the current aspect of glycosylation reaction, which is in turn described ; utilization of glycosyl halide derivatives, of 1, 2-orthoester sugar derivatives, of 1-O-acyl sugar derivatives, of 1-OH sugar derivatives, and of other sugar derivatives for the reaction.
TL;DR: In this article, the usefulness of DAD as an oxidant has been extended to syntheses of a wide variety of heterocycles, and a review summarizes the synthetic application of these DAD-dependent oxidations.
Abstract: Diethyl azodicarboxylate (DAD) is a strong hydrogen acceptor and is capable of oxidizing several hydrogen or electron donors to give the corresponding oxidation products. The usefulness of this reagent as an oxidant has been extended to the syntheses of a wide variety of heterocycles. This review summarizes the synthetic application of these DAD-dependent oxidations. Additionally oxidative dealkylation reactions are mentioned.
TL;DR: In this paper, a review of synthetic methods for layered cyclophanes with polycyclic aromatic nuclei has been presented, and eleven categories and reactivities of the compounds are described.
Abstract: Recently a number of layered compounds, especially layered cyclophanes, with polycyclic aromatic nuclei have been reported. Such compounds, in which condensed aromatic rings are closely fixed with each other, or with other π-systems, often show unusual physical and chemical properties. In this review synthetic methods for layered cyclophanes are classified into eleven categories and reactivities of the compounds are described.
TL;DR: Various relevant methods of synthesis are progressively reviewed on optical resolutions followed by racemizations, a stereoselective synthesis and/ or a synthesis by asymmetric induction of optically active chrysanthemic acids in close reference to the insecticidal activities of resultant stereoisomers.
Abstract: Initially, a number of important or established synthetic pyrethroids containing the chrysanthemate moiety are introduced, and there are also described the relative insecticidal potencies of specific stereoisomers of the chrysanthemates resulting from acid stereochemistry. Recently, many studies on structure modification of the acid moiety of pyrethroid have disclosed a number of the most distinguished synthetic pyrethroids containing diversely modified acid moieties, which have been successfully developed as the most outstanding pyrethroid insecticides in the recent years.Since a majority of the chrysanthemates now have been reinforced on the insecticidal potency basis by the synthetic selection of useful stereoisomers, various relevant methods of synthesis are progressively reviewed on optical resolutions followed by racemizations, a stereoselective synthesis and/ or a synthesis by asymmetric induction of optically active chrysanthemic acids in close reference to the insecticidal activities of resultant stereoisomers. Relevant methods leading to all the fenvalerate stereoisomers and specific stereoisomer mixtures resulting from the chirality of the alcohol moiety are also described.Finally, some of specific advantages that are delivered by the stereoisomer selection are commented regarding the insecticidal performance aspects essentially linked with developmental potentials of the synthetic pyrethroids.
TL;DR: In this paper, the characteristics of a carbon-fluorine bond from the biological point of view are summarized with some examples: mimic effect, protective fluorination, irreversible conjugation with enzyme, increased lipophilicity and so on.
Abstract: First, characteristics of a carbon-fluorine bond from the biological point of view are summarized with some examples : mimic effect, protective fluorination, irreversible conjugation with enzyme, increased lipophilicity and so on are presented. Secondly, some approaches to biologically active compounds utilizing the above characteristics are shown by the examples of trifluoromethylated nucleoside derivatives and fluorinated vitamin D3 analogues.
TL;DR: In this paper, a review of the recent development of C-H and C-O bonds activation by transition metal complexes is described, and the application of the oxidative addition of CH and O bonds to organic synthesis is also described.
Abstract: Recent developement of C-H and C-O bonds activation by transition metal complexes is described. In this review, oxidative addition of C-H and C-O bonds toward transition metals accompanied by the bond breakage of these bonds is regarded as an important step of the activation. Application of the oxidative addition of C-H and C-O bonds to organic synthesis is also described.
TL;DR: In this paper, Wacker type oxidation of terminal double bonds to methyl ketones catalyzed by PdCl2-CuCl is used in key steps for natural product synthesis.
Abstract: Butadiene telomers, easily prepared by the palladium-catalyzed telomerization of butadiene with various nucleophiles are extremely useful starting materials for natural product syntheses. The following natural products were synthesized in short steps by using several butadiene telomers : Steroid (19-nortestosterone), macrolides (diplodialides, 9-decanolides, lasiodiplodin, zearalenone, recifeiolide, curvularin), Matsutake alcohol, lipoic acid, pellitorin, dihydrojasmone, methyl dihydrojasmonate, muscone, civetone, pyrethrolone, 12-acetoxy-1, 3-dodecadiene, royal jelly acids and queen substance. In these syntheses, Wacker type oxidation of terminal double bonds to methyl ketones catalyzed by PdCl2-CuCl is used in key steps.
TL;DR: The reactions of triphenylphosphine -thiocyanogen (TPPT) with various nucleophiles are reviewed in this paper, which can be classified by the following two features: a) as observed in the reaction with amines, organometallic compounds, indoles and pyrroles, nucleophilic addition to the -N=C=S carbon of TPPT, giving thiocarbamoylated compounds (Type B).
Abstract: The reactions of triphenylphosphine -thiocyanogen (TPPT), prepared by a combination of equimolar amount of triphenylphosphine and thiocyanogen, with various nucleophiles are reviewed. It can be classified by the following two features: a) as observed in the reaction with alcohols, carboxylic acids, and epoxides, nucleophilic attack on the phosphorus atom of TPPT followed by substitution of the SCN anion on the adjacent carbon to oxygen atom of the intermediate with elimination of triphenylphosphine oxide, giving the thio-and/or isothiocyanates (Type A) and b) as observed in the reaction of amines, organometallic compounds, indoles and pyrroles, nucleophilic addition to the -N=C=S carbon of TPPT, giving thiocarbamoylated compounds (Type B). Synthetic utilities of TPPT are also summarized.
TL;DR: Bestatin enhanced delayed- type hypersensitivity, and was found to be effective against experimented murine tumors by bestatin alone and also enhanced the therapeutic effect of antitumor agents such as bleomycin and adriamycin.
Abstract: In the course of screening of immunostimulator from microbial secondary metabolites, bestatin was isolated from the culture filtrate of Streptomyces olivoreticuli as an inhibitor of aminopeptidase B. The structure of bestatin was determined to be (2S, 3R) -3-amino-2-hydroxy-4-phenylbutanoyl-L-leucine. General synthetic methods of 3-amino-2-hydroxy acids from α-amino acids and α, β-unsaturated esters were established, and structure-activity relationships between bestatin analogues and inhibition of aminopeptidase B were discussed. Bestatin enhanced delayed- type hypersensitivity, and was found to be effective against experimented murine tumors by bestatin alone and also enhanced the therapeutic effect of antitumor agents such as bleomycin and adriamycin. Bestatin is well adsorbed by oral administration and excreted into urine. It does not show any toxic sign. Bestatin is now clinically tested as an immunotherapeutic agent against cancer.
TL;DR: In this paper, it was shown that the reactions with nucleophiles under basic conditions proceed through SN2 type substitution and no serious problem on both mechanism and stereochemistry remains unsolved.
Abstract: Ring-opening of epoxide involves two major subjects of study, positional selectivity and stereochemistry. It appears that the reactions with nucleophiles under basic conditions proceed through SN2 type substitution and no serious problem on both mechanism and stereochemistry remains unsolved. In contrast, the results under acidic conditions are confusing. We have critically discussed the mechanisms proposed so far and shown our conclusion. On the basis of this conclusion together with a new concept of microscopic structure of solvation, the wide range changes of stereochemistry of acid catalyzed solvolysis of stilbene oxide from inversion to retention in binary solvents have been explained. This idea might be applicable to the other types of solvolysis.
TL;DR: In this article, the authors reviewed the progress in synthetic studies on 1-oxacephems and discussed the antibacterial activity of 7α-methoxy-1oxachem compounds.
Abstract: Progress in synthetic studies on 1-oxacephems is reviewed. Antibacterial activity of this new class of compounds is also discussed briefly. Earlier syntheses, rather lengthy but quite pioneering, provided us with valuable information of the interesting biological activity of 1-oxacephems. Several improved synthesis have appeared, enabling to prepare a variety of derivatives and examine their antibacterial activity. Thus, syntheses and antibacterial activity of some interesting 1-oxacephems and 7α-methoxy-1-oxacephems, such as, arylmalonamido-, α-acylureidophenylacetamido-, and α-aminothiazolyl-α-methoxyiminoacetamido derivatives with representative 3'-substituents are described. A compound 6059-S 98 discovered in Shionogi Research Laboratories, proved to have excellent antibacterial activity, spectrum, and other pharmacological properties and, therefore, is currently under clinical studies. An industrially feasible synthetic method for its nucleus 88 a as well as 7α-methoxy-1-oxacephem nuclei with a variety of substituents at the 3'-position in general was established after extensive studies.
TL;DR: Theater-goers are urged to consider their options before committing to a playwrights’ course of action.
Abstract: 酵素モデルとしての大環状化合物を分子設計する場合に三つの基本的な構造形式が考えられる。すなわち, 図1に示すように環状空洞口の両側が開放されたままで蓋がないA型, 片側にのみ蓋があるB型, 両側とも蓋があるC型である。酵素モデルとしては通常環空洞内部および蓋の部分は疎水性をもつことが必要である。水溶液中で疎水性基質を取りこむためにはホストである大環状化合物の空洞がバルク相からなるべくしゃへいされている方が効果的である。従って, 基質を取りこむためだけであればA型よりもB型, B型よりもC型の方が優利であるはずである。勿論C型については少なくとも一方の蓋は可動であり, 基質の取りこみ過程では開口する柔軟構造でなければならない。A型であれば基質が一方の空洞口から入ってきて, 生成物は他方の口から出ていくことになる。ところがB型になると基質が入ってきた口から生成物も出て行かなければならず, 分子運動エネルギーの損失がある。C型になると事態はもう少し複雑である。開口性蓋から入ってきた基質は空洞内で反応して生成物が同じ蓋から出ていくとしよう。基質と生成物の疎水性などの物性は同一でないと考えられるので, 基質が取りこまれ易ければ出て行き難いということになり, 触媒としての再生に問題がありそうである。図1では分解反応の例を示しているが, 矢印の方向を逆にできれば合成反応になる。大環状空洞内は一種のmagic boxであるといえよう。いかに高度の魔術性をもたせるかは分子設計次第であり, 酵素モデルの価値を左右することになる。大環状化合物は会合状態でなく単量体として触媒機能を発現することができ, その構造は媒体の組成, イオン強度, pH, 温度などの外的条件に実際的にはほとんど左右されない。しかも触媒官能基は大環状骨格に固定されるため触媒基間の立体配置なども分子模型により確かめることができる。従って, 合成上の難易などの問題点はあるとしても, 空間充填型のCPK分子模型を用いることによりα一キモトリプシンの機能として提案されている電荷リレー系など酵素の活性中心の機能要因を大環状化合物で構築することも原理的には可能である。本小文では代表的な環状化合物であるシクロデキストリン, クラウンエーテル, シクロファンなどについてその特性を解説したい。