巻号一覧
54 巻, 9 号
選択された号の論文の8件中1～8を表示しています
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秦 英一郎, 加藤 穂慈, 山田 徹, 向山 光昭1996 年 54 巻 9 号 p. 728-739
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーNitrosation of various α, β-unsaturated carbonyl compounds with nitrogen monoxide or butyl nitrite was achieved in the presence of silane and a catalytic amount of N, N' -bis (2-ethoxycarbonyl-3- oxobutylidene) ethylenediaminatocobalt (II) complex catalyst. In the presence of a catalytic amount of tris (1, 3-diketonato) iron (III) complex, various terminal and 1, 2-disubstituted olefins were converted into the corresponding nitroso alkane dimers in fairly good yields on treatment with phenylsilane and butyl nitrite.
Nitration of various terminal olefins into corresponding nitro olefins were performed on treatment with nitrogen monoxide. Nitroalcohols, minor coproducts, were dehydrated to yield nitro olefins by the subsequent treatment with acidic activated aluminum. By GC analysis, evolution of an equimolar amount of nitrogen gas was observed during the present nitration. A possible reaction pathway including the formation of nitro nitroso compounds, key intermediates, was proposed.抄録全体を表示PDF形式でダウンロード (1648K) -
砂塚 敏明, 長光 亨, 大村 智1996 年 54 巻 9 号 p. 740-751
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーA total synthesis of the microbial metabolite (+) -lactacystin (1), the first non-protein neurotrophic agent, has been achieved in 11 steps (14% overall yield) from 2 (R), 3 (S) -3-hydroxyleucine. The key steps in the elaboration of the lactam moiety include the stereoselective hydroxymethylation of oxazoline and an asymmetric allylboration of the aldehyde which introduce the hydroxyl and methyl substituents at C (6) and C (7).
This new asymmetric approach furnished four stereoisomers of 3-hydroxyleucine as required starting material in high overall yield and enantiomeric purity.
Furthermore, the construction of several active analogs and the structure-activity relationships of lactacystin are also described.抄録全体を表示PDF形式でダウンロード (1046K) -
大坪 徹夫, 安蘇 芳雄, 瀧宮 和男1996 年 54 巻 9 号 p. 752-760
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーThe developments of novel electron donors of non-TTF types are described, especially focussing on peri-condensed heteroarenes bearing a structural resemblance to pyrene or perylene and on peri-dichalcogen bridged arenes like tetrathiotetracene. These compounds have been designed chiefly to provide strong donating abilities and strong intermolecular heteroatomic contacts, which are prerequisites for components of organic metals. As a result, some of them have stronger donating abilities than does tetrathiafulvalene (TTF), thus providing a large number of highly conducting molecular complexes.抄録全体を表示PDF形式でダウンロード (1004K) -
砂川 洵, 佐々木 章1996 年 54 巻 9 号 p. 761-771
発行日: 1996/09/01
公開日: 2010/01/28
ジャーナル フリー1976年にチエナマイシン (1) の発見が報告されて以来丁度20年が経過した。1は強力かつ幅広い抗菌活性という抗菌剤としての必要条件を満たしていたが, 化学的安定性, 生体内安定性 (デヒドロペプチダーゼ-I, DHP-Iに対する安定性) および, 腎毒性, 中枢毒性などの副作用面で克服すべき課題を有していた。
その必要条件を維持し, いかに医薬品としての十分条件を満たすかという命題のもと多くの研究グループによってカルバペネム抗生剤の開発研究が展開された。その結果, これまでにイミペネム (2), パニペネム (4), メロペネム (6) の3剤が市販されている (図1) 。2および4はいずれも腎毒性の低減などを目的にそれぞれDHP-I阻害剤・シラスチタン (3), 有機アニオン輸送阻害剤・ベタミプロン (5) との合剤として開発された。したがって, 安全性, 使いやすさなどからカルバペネム単剤での開発が望まれていたが, 近年DHP-Iに対する安定性が向上することで注目された1β-メチルカルバペネム骨格を持っメロペネム (6) の開発がその夢を実現し, カルバペネム抗生剤の開発研究は1っの峠を越えたということができる。
カルバペネム抗生剤の開発研究における合成化学の比重は極めて高く, その研究のほとんどが全合成によって展開された。合成法の開発が新しい誘導体での探索を可能ならしめ, その進歩が大量製造を可能ならしめ, その結果としてカルバペネム抗生剤開発に至ったというこれまでの経緯が, 合成化学の果たした役割の重さを如実に示しているが, 同時にカルバペネム合成化学は基盤が確立し, 次なる展開を図る時期にきたことを示している。既に多くの総説があるが本稿では “新世代カルバペネム抗生剤の開発” を目指した今後の研究を展望すべく, 最近の報文を中心に合成化学の現状を概説するとともに, 生物活性面から見たカルバペネム化学について触れる。抄録全体を表示PDF形式でダウンロード (1503K) -
尾島 十郎, 樋口 弘行, 山本 学1996 年 54 巻 9 号 p. 772-782
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーOur recent studies on synthesis, stereochemical analysis, and tropicity of various dehydroannulenes, annulenones, annulenediones, cross-conjugated annulene derivatives, and heteraannulenes are reviewed. Our efforts consist mainly of the design and construction of novel peripherally conjugated systems and the exploration of the highest member in each series of compounds exhibiting tropicity.抄録全体を表示PDF形式でダウンロード (1223K) -
富岡 秀雄, 平井 克幸1996 年 54 巻 9 号 p. 783-793
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーIn order to stabilize triplet carbenes kinetically to extent that they are able to survive under normal conditions, attemps were made to protect the carbenic center of triplet diphenylcarbenes by introducing a series of substituents at the ortho position. Thus, diphenylcarbenes bearing chloro, methyl, t-butyl and bromo groups at the ortho positions were generated by photolysis of the corresponding diazo compounds and were characterized not only by product analysis but also by direct observation using spectroscopic means. Thus, decachloro- and decamethyldiphenylcarbenes were shown to be four and five orders of magnitude longer-lived than the parent diphenylcarbene, respectively. The replacement of all the o-CH3 groups of decamethyldiphenylcarbene with CD3 groups greatly decreased the intramolecular H abstraction rate from the o-methyl groups and resulted in the formation of triplet carbene having half-life over second in solution at room temperature for the first time. On the other hand, t-butyl group was shown to be disappointingly less effective protector of the triplet carbene due to its ability of H transfer to the carbenic center.
2, 2', 4, 4', 6, 6'-Hexabromodiphenylcarbene was found to be very persistent in the triplet states. Thus, EPR signals of the carbene generated in single crystals of the diazomethane survived up to room temperature without loss of intensity for months. In 2-methyltetrahydrofuran matrix the carbene showed no decomposition even at 120 K where the samples were completely fluid. Replacement of bromine groups at 6 and 6' positions of the hexabromodiphenylcarbene with t-butyl groups resulted in increase in the lifetime of the triplet carbene under normal conditions to ca 20 seconds which is 108 times longer lived than the parent diphenylcarbene.抄録全体を表示PDF形式でダウンロード (1561K) -
曽根 孝範1996 年 54 巻 9 号 p. 794-800
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーA series of isoquinolinesulfonamide derivatives were synthesized and shown to possess vasodilatory action. 1- (5-Isoquinolinesulfonyl) homopiperazine hydrochloride (fasudil) had more potent vasodilatory effect to vertebral artery than diltiazem. Fasudil inhibits protein kinase and dilates spastic cerebral arteries in the canine two-hemorrhage model. In clinical studies with fasudil administered by intravenous injection in patients who had undergone sugery for subarachnoid hemorrhage, fasudil significantly reduced the occurrence of vasospasm. In Japan, fasudil was approved in june, 1995.抄録全体を表示PDF形式でダウンロード (881K) -
砂塚 敏明, 大坪 徹夫, 富岡 秀雄1996 年 54 巻 9 号 p. 801
発行日: 1996/09/01
公開日: 2009/11/16
ジャーナル フリーPDF形式でダウンロード (165K)
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