...Quantum chemical laws that explain or predict the thermophotoselectivity (whether it occurs with heat or light) and stereoselectivity (what will be the stereochemistry of the product) of certain organic chemical reactions. In 1965, Americans R.B. Woodward (1917-79) and R. Hoffman (1937- ) provided explanations based on molecular orbital theory for previously unexplained phenomena in organic chemical reactions, namely, (1) that some reactions proceed only with heat and others only under the influence of light, and (2) that some reactions produce products with high stereoselectivity, and that the stereochemistry of the products often differs between thermal and photoreactions. Because this theory is related to the symmetry of molecular orbitals, it is also called the law of conservation of orbital symmetry. ... From [Chemistry]...A. Windaus worked on cholesterol, and HO Wieland on bile acids, and after many twists and turns, they clarified their structures by the 1930s. Around the same time, the sex hormone dl -equilenin was totally synthesized, and in 1952, Robert Burns Woodward (1917-79) succeeded in totally synthesizing cholesterol. Around the same time, Woodward also worked on the total synthesis of strychnine (an alkaloid), tetracycline (an antibiotic), chlorophyll a, vitamin B12 , and others. ... From [Organic Chemistry]...Theoretical methodologies such as the Hückel molecular orbital method were recognized as useful for understanding the physical properties and structures of organic compounds, and gradually came to be used. Kenichi Fukui's frontier orbital theory (1952), Robert Burns Woodward's (1917-79) and Roald Hoffman's (1937- ) orbital symmetry rules (1965), and others were widely used as practical theories that could be applied to organic synthesis. In the last quarter of the 20th century, organic chemistry has seen remarkable development in two fields: organic synthetic chemistry, which achieves stereocontrol of reactions, and biomimetic organic chemistry, which attempts to reproduce some of the complex functions of living organisms in the laboratory. ... *Some of the terminology that mentions "Woodward, RB" is listed below. Source | Heibonsha World Encyclopedia 2nd Edition | Information |
…ある種の有機化学反応の熱光選択性(熱で起こるか光で起こるか)および立体選択性(生成物の立体化学がどうなるか)を説明または予測するための量子化学的法則。1965年アメリカのR.B.ウッドワード(1917‐79)とR.ホフマン(1937‐ )は,それまで説明のつかなかった有機化学反応の諸現象,すなわち,(1)熱によってしか進行しない反応もあれば光の影響下でしか進行しない反応もあること,(2)反応によっては立体選択性の高い生成物が得られ,しかも熱反応と光反応でその立体化学がしばしば異なること,などに対して分子軌道論に基づく説明を与えた。分子軌道の対称性に関係する理論であることから軌道対称性保存則とも呼ばれる。… 【化学】より…A.ウィンダウスはコレステロールに,H.O.ウィーラントは胆汁酸に取り組み,紆余曲折はあったが1930年代までにそれらの構造を明らかにした。同じころ性ホルモンのdl‐エキレニンの全合成がなされ,さらに1952年にはウッドワードRobert Burns Woodward(1917‐79)がコレステロールの全合成に成功した。ウッドワードは相前後して,ストリキニーネ(アルカロイド),テトラサイクリン(抗生物質),クロロフィルa,ビタミンB12などの全合成を手がけた。… 【有機化学】より…ヒュッケル分子軌道法に代表される理論的方法論は,有機化合物の物性や構造の理解に役立つことが認められ,しだいに利用されていった。福井謙一のフロンティア軌道理論(1952),ウッドワードRobert Burns Woodward(1917‐79)とホフマンRoald Hoffman(1937‐ )の軌道対称則(1965)などは,有機合成にも応用できる実際的な理論として大いに利用された。 20世紀の最後の四半世紀において,有機化学は反応の立体制御を実現しながら進める有機合成化学と,生体の複雑な機能の一部を実験室で再現しようという生体模倣有機化学biomimetic organic chemistryの2分野に著しい発展がみられている。… ※「ウッドワード,R.B.」について言及している用語解説の一部を掲載しています。 出典|株式会社平凡社世界大百科事典 第2版について | 情報 |
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