著者
橋本 貴美子 犀川 陽子 中田 雅也
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.64, no.12, pp.1251-1260, 2006-12-01 (Released:2010-10-20)
参考文献数
21
被引用文献数
1 3

Hippopotamus produces colorless sweat over its entire body. The color of the sweat turns red within a few minutes and then becomes brown during a few hours by producing polymers. We isolated the unstable red and orange pigments, called hipposudoric acid and norhipposudoric acid, respectively, responsible to the red coloration of the sweat. Syntheses of these pigments were performed using the Pschorr reaction for the formation of the fluorenone core and the oxidation in the last step producing the unstable diquinone as the key steps. The tautomeric structures of the common chromophore of these pigments in a protic solvent and in an aprotic solvent were also discussed.
著者
森田 泰彦
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.48, no.5, pp.416-417, 1990-05-01 (Released:2009-11-13)

L-アスコルビン酸 (以下L-AsAと略す) は抗壊血病活性をもつ水溶性ビタミンで一般にはビタミンCとして知られている。AsAにはL-体とD-体とが存在するが, 抗壊血病作用をもつのはL-体でD-体はほとんど作用がない。1920年に抗壊血病作用を示す成分がビタミンCと〓命名された (Drummondにより) が, その後Szent-Gyorgyiらがウシの副じん (腎), オレンジ, キャベッ等から結晶として単離してヘキスロン酸と命名した物質がビタミンCと同一物質であることが確認され, 抗壊血病の意味からアスコルビン酸と命名された。天然にはかんきつ (柑橘) 類, そ (蔬) 菜類, 緑茶等に多く含まれているが, 純度の高い結晶が容易に大量生産されるので天然物から抽出, 単離することは行われていない。
著者
瀬川 泰知 長瀬 真依 齋藤 雄太朗 加藤 健太 伊丹 健一郎
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.80, no.11, pp.994-999, 2022-11-01 (Released:2022-11-05)
参考文献数
42

The selective and predictable C-H functionalization of arenes is a valuable method for the synthesis and modification of organic molecules in which regioisomer formation is often controlled by electronic factors or the presence of coordinating groups. On the other hand, the iridium-catalyzed C-H borylation of arenes can achieve unique steric-controlled regioselectivity. In this account, we describe our recent studies on the iridium-catalyzed C-H borylation of arenes: the development of novel catalytic systems that exhibit steric-controlled para-selectivity for mono- and unsymmetrically 1,2-disubstituted benzenes; and their application to the functionalization of large polycyclic aromatic hydrocarbons (molecular nanocarbons).
著者
金城 玲
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.79, no.11, pp.1056-1064, 2021-11-01 (Released:2021-11-10)
参考文献数
30
被引用文献数
1

The concept of aromaticity has been of paramount significance in myriad fields of chemistry. To modulate the intrinsic electronic nature of aromatic molecules, partial incorporation of heteroatoms into the benzene scaffold represents a useful strategy in modern inorganic chemistry. This account presents how to incorporate boron into aromatic six-membered scaffolds, leading to hybrid organic/inorganic benzenes, namely diazadiborinines. In addition, their reactivity towards a variety of substrates are summarized.
著者
森田 昌敏
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.39, no.11, pp.1083-1096, 1981-11-01 (Released:2009-11-13)
参考文献数
73
被引用文献数
1 2

生体に取り込まれた金属は血流にのって移動し, いろいろな臓器に到達し, 様々な化学変化を受けながら, 一部は貯蔵 (あるいは蓄積) され, 残りは排泄されていく。吸収から始まる, これらの一連のプロセスは, 各種のフィードバック回路を内蔵した化学反応系であるが, その内容は非常に複雑精緻であり, 今日においても未解明の部分が多い。本稿では, 重金属の生体内での代謝を, 吸収, 輸送, 体内分布, 排泄にわけて記述した。重金属の代謝に関する研究は, 栄養学, 毒物学を中心とし, 分析化学や生化学のような基礎科学から臨床医学のような応用科学まで広い範囲の研究者によってなされてきており, その記述内容は著者のバックグランドによって, かなり左右される。ここでは科学者から見た代謝が書かれている。分析技術の最近の進歩についても若干触れている。

11 0 0 0 OA 食用色素の化学

著者
片山 脩
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.32, no.8, pp.620-631, 1974-08-01 (Released:2009-11-13)
被引用文献数
1 1

食事は芸術であるという考え方は, フランス人だけのものではないように思う.日本料理の形のよさ, 色どりの美しさ, また微妙な味付は芸術にふさわしいものであろう.食品の評価には衛生的, 栄養的因子もさることながら, 味, 香, 色, 形, 口ざわりなど, いわゆる官能的価値も重要因子として関係してくる.したがって加工食品においては, これらの質の改良を目指して技術の開発が進められてきた.とくに加工度の進んだ最近の食品では, 機械的処理と化学物質の添加処理が複雑に組合わさった方式で製造される.したがって化学物質を用いずしては, その加工法が成立しないという場合が非常に多い.食品の着色や変色の防止についても多くの工夫がなされ, 古くは天然の動植物体あるいは鉱物に含まれる色素が着色のために用いられた.しかし19世紀中頃にいたって合成染料であるタール系色素が開発され, その染着力の強さ, 色の鮮かさ, 均質性, 安定性の高いこと, 安価であることなどの長所が大きくその用途を拡張したが, 食用にも多種類のタール系色素が利用されるようになった.わが国においても昭和39年には24種類のタール系が許可されていた.しかしタール系色素には発ガン性など毒性をもつおそれのあることが指摘され, アメリカ, その他でタール系色素の使用が制限されはじめたことから, 日本においても昭和40年に赤色1号, 赤色101号, 41年には赤色4号と5号, 橙色1号と2号, 黄色1号と2号および3号が, また42年には緑色1号, 45年に緑色2号, 46年に赤色103号, 47年に紫色1号が使用禁止となり現在では, 後述のような11種が残されるのみとなった.これら残されたタール系食用色素は一応かなり安全性が高いと考えられているが, 確定的な結論はなお今後の検討にまたねばならない.このようにタール系色素の使用がいちぢるしく制限されるようになったため, 再び天然色素の利用が注目されるようになり, そのための原料の検索, 製剤化, 利用面の開拓などの研究や技術開発がさかんになろうとしている.こうした事情を考慮すると, これからの食用着色料はタール系色素と天然色素のそれぞれの特徴を生かし, 組合わせた状態で使用されるという方向に進むものと思われる.本稿では, タール系色素を中心として述べるが, 天然色素についても主なものの構造, 性質等について解説することにしたい.
著者
西出 喜代治 野出 學
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.62, no.9, pp.895-910, 2004-09-01 (Released:2010-01-22)
参考文献数
39
被引用文献数
15 15

Development of odorless thiols [1-dodecanethiol (Dod-SH), 4-trimethylsilylphenylmethanethiol (TMSBM), 4-trimethylsilylbenzenethiol (TMSBT), and 6-morpholinohexanethiol (MHT)] and odorless sulfides [dodecyl methyl sulfide (Dod-S-Me), methyl 6-morpholinohexyl sulfide (MMS)] and their sulfoxides [dodecyl methyl sulfoxide (Dod-S (O) -Me), methyl 6-morpholinohexyl sulfoxide (MMSO)] as odorless substitutes for the foul-smelling ethanethiol, benzyl mercaptan, benzenethiol, and dimethyl sulfide (DMS) is described. They are conveniently applied for dealkylation, thiol exchange reaction, reductive ozonolysis, Corey-Kim oxidation, Swern oxidation, hydroboration, and reduction. The products of these reactions utilizing morpholine based thiol MHT, sulfide MMS and its sulfoxide MMSO can be easily purified by only acid-base extraction without involving chromatography, thereby eliminating unpleasant odors, saving time and protecting the environment. In view of current environmental and economic factors, the utility of these simple reagents could be enormously beneficial.
著者
林 雄二郎
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.63, no.5, pp.464-477, 2005-05-01 (Released:2009-11-13)
参考文献数
106
被引用文献数
73 77

In the early 1970s, intramolecular aldol reaction catalyzed by proline was reported by Hajos et al., and its intermolecular version was discovered by List, Barbas, and Lerner in 2000. In the same year, MacMillan reported the asymmetric Diels-Alder reaction catalyzed by organocatalyst by lowering the LUMO energy of enones by the formation of iminium salt. After these two seminal papers, chiral small organic molecules have been widely employed in asymmetric synthesis because they have several advantages over the conventional transition metal based catalysts. Organic catalysts are inexpensive, readily available, and non-toxic. They are not sensitive to moisture and oxygen. The products are free from the contamination of metals. Because of these advantages, this field has been expanding so rapidly. Though there are so many asymmetric reactions catalyzed by organocatalysts, this article briefly summarizes the recent progress in the following reactions because of the limitation of space : Aldol reaction, Mannich reaction, Michael reaction, functionalization of α-position of carbonyl compounds, cycloaddition reactions such as Diels-Alder reaction, [3+2] cycloaddition reaction, and [4+3] cycloaddition reaction, allylation, Morita-Baylis-Hillman reaction, epoxidation, and phase-transfer reaction.
著者
宮浦 憲夫 鈴木 章
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.46, no.9, pp.848-860, 1988
被引用文献数
1 13

A general and convenient method for the stereo-and regioselective synthesis of conjugated alkadienes, alkenynes, arylated alkenes, and heterobiaryls is described. The reaction of (<I>E</I>) -or (<I>Z</I>) -1-alkenylboronates obtainable by hydroboration, with either (<I>E</I>) -or (<I>Z</I>) -1-alkenyl halides in the presence of a catalytic amount of tetrakis (triphenylphosphine) palladium and bases such as sodium alkoxides gives the corresponding (<I>E</I>, <I>E</I>) -, (<I>E</I>, <I>Z</I>) - (<I>Z</I>, <I>E</I>) -and (<I>Z</I>, <I>Z</I>) -alkadienes stereo-and regioselectively, while retaining the configuration of both the starting alkenylboronates and haloalkenes The similar reactions of (<I>E</I>) -and (<I>Z</I>) -1-alkenylboronates with 1-alkynyl, aryl, allylic, and benzylic halides also provide the corresponding couplig products stereosoelectively. The versatility of this method has been demonstrated by the synthesis of some natural products bearing conjugated alkadiene structures. The reaction of arylboronic acids with aryl halides to give unsymmetrical biaryls is also presented. A mechanism of this cross-coupling reaction, which involves the transmetallation between a 1-alkenylborane and an alkoxopalladium (II) complex generated through the metathetical displacement of a halogen atom of RPd (II) X with sodium alkoxide, is proposed.
著者
西沢 麦夫
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.51, no.7, pp.631-640, 1993-07-01 (Released:2010-01-28)
参考文献数
51
被引用文献数
1 2

Significant attentions have been focused on the inclusion chemistry of cyclodextrins and the related compounds and synthetic studies of cyclooligosaccharides have been tarring out intensively. For example, Ogawa and coworkers reported the total synthesis of cyclodextrins and a manno isomer of cyclodextrins by means of phenylselenyl triflate promoted cycloglycosylations. Synthesis of 1-3β linked cycloglucohexaose was reported by Collins' group. Modifications of α-cyclodextrin into trimethyl, 1, 3-anhydro, and a chimera analog have also reported recently. However, cyclooligosaccharide available today is only limited to D series. As we have developed a novel thermal glycosylation procedure, which can be applied to rhamnosylation with high α-selectivity, we designed the synthesis of cyclo-L-rhamnohexaose (40), the first cyclooligosaccharide of L series. On the basis of the area where the compound has been prepared, this compound was named α-cycloawaodorin, which would open a new dimension of the inclusion chemistry.
著者
榊原 陽太 伊丹 健一郎 村上 慧
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.81, no.11, pp.1050-1061, 2023-11-01 (Released:2023-11-10)
参考文献数
56
被引用文献数
1

Carboxylic acids are one of the most important functional groups found in various feedstocks. Their significance lies in their pivotal role as key intermediates in selective transformations during organic synthesis. Despite the existence of various decarboxylative transformation reactions such as Kolbe dimerization, these methods still exhibit certain limitations that present opportunities for further improvement. In this account, we present our recent studies on the application of photocatalytic decarboxylative transformation that allows the divergent transformation of carboxylic acids.
著者
和佐 雅幸 Ahmet Yesilcimen
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.79, no.11, pp.1065-1072, 2021-11-01 (Released:2021-11-10)
参考文献数
182
被引用文献数
2

Cooperative actions of two or more Lewis acid and/or Lewis base catalysts can be exploited to promote enantioselective transformations that are not readily achieved by a single catalyst system. Nonetheless, undesirable acid-base complexation which occurs in a reaction mixture containing the catalysts, substrates, and products often results in poor reaction efficiency and a contrived substrate scope. In this article, we highlight our development of multi-catalyst systems that facilitate enantioselective transformations of otherwise unreactive C-H bonds contained in various carbonyl compounds and N-alkylamines while overcoming the formation of inert Lewis adducts. Such methods were achieved through the identification of catalyst/substrate combinations that form frustrated Lewis pairs (FLPs), namely, highly active acids and bases whose mutual quenching is precluded due to steric and electronic factors.
著者
山田 静之 木越 英夫
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.53, no.1, pp.13-21, 1995-01-01 (Released:2009-11-16)
参考文献数
22

Synthetic studies on the bracken ultimate carcinogen (3) and its artificial analogues (32, 33) are described. The synthesis of (-) -ptaquilosin (2) the aglycon of a potent carcinogen ptaquiloside (1) from bracken and its (+) - enantiomer (ent- 2) was achieved starting with (+) -dimenthyl (1R, 2R) -cyclopentane-1, 2-dicarboxylate. Dehydration of ptaquilosin (2) under weakly basic conditions led to the ultimate carcinogen (3). DNA cleaving activities of both enantiomers (3) were compared, the one (3) derived from natural (-) -ptaquilosin (2) being more efficient. Reactivities of the ultimate carcinogen (3) toward DNA are described. DNA was shown to be alkylated at the particular sites of purine bases and to undergo cleavage. The molecular mechanism of DNA cleavage with the ultimate carcinogen (3) was disclosed using deoxytetranucleotide d (GTAC) as a model DNA substrate.