- One-step synthesis of isocoumarins and 3-benzylidenephthalides via ligandless pd-catalyzed oxidative coupling of benzoic acids and vinylarenes
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A straightforward synthetic method for the preparation of isocoumarins and 3-benzylidenephthalides via C-H olefination and oxidative coupling of readily available benzoic acids and vinylarenes was developed. The directing effect of the substituents on the benzoic acid allows for the synthesis of both types of lactone in pure form.
- Nandi, Debkumar,Ghosh, Debalina,Chen, Shih-Ji,Kuo, Bing-Chiuan,Wang, Nancy M.,Lee, Hon Man
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p. 3445 - 3451
(2013/08/14)
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- Synthesis of 3-substituted isocoumarins and their inhibitory effects on degranulation of RBL-2H3 cells induced by antigen
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Eleven 3-substituted isocoumarins and a benzylidenephthalide were synthesized through thermal cyclization reaction of δ- and γ-ketoamides, respectively. Subsequent deprotection of the hydroxyl groups of the resulting isocoumarin and benzylidenephthalide compounds afforded thunberginols A, B, and F., respectively, which originated from the processed leaves of Hydrangea macrophylla Seringe var. thunbergii MAKINO. The synthesized isocoumarins and thunberginols were evaluated for their anti-allergic activity, in which thunberginol B exhibited the highest inhibitory potency on the degranulation of RBL-2H3 cells induced by antigen. Structure - activity relationship studies were carried out to determine the necessary substituents on the 3-phenylisocoumarin skeleton for inhibitory activity.
- Kurume, Ai,Kamata, Yasuhiro,Yamashita, Masayuki,Wang, Qilong,Matsuda, Hisashi,Yoshikawa, Masayuki,Kawasaki, Ikuo,Ohta, Shunsaku
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experimental part
p. 1264 - 1269
(2009/09/25)
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- Synthesis of naturally occurring (Z)-3-benzylidenephthalide and (+/-) 3-benzylphthalides
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A convenient method, involving generation of phthalide anion, is described for the synthesis of naturally occurring (Z) 3-benzylidenephthalide (5) and (+/-) 3-benzyl phthalides (6c, 10a-c), starting from phthalides (7a-b).
- Mali, Raghao S.,Massey, Archna P.,Talele, M. I.
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p. 472 - 490
(2007/10/03)
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- Facile synthesis of thunberginol F
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A new and convenient synthesis of (Z)-3-(3,4-dihydroxybenzylidene)-7-hydroxyphthalide (5) is described starting from 3-hydroxy-7-methoxyphthalide (1).
- Wang, Zhi-Wei,Li, Shao-Bai,Li, Yu-Lin
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p. 363 - 364
(2007/10/03)
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- Development of bioactive functions in Hydrangeae Dulcis Folium. VI. Syntheses of thunberginols A and F and their 3'-deoxy-derivatives using regiospecific lactonization of stilbene carboxylic acid: Structures and inhibitory activity on histamine release of hydramacrophyllols A and B
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Lactonization reaction of 2-carboxystilbene mediated by copper(II) chloride proceeded regiospecifically to give the five-membered lactone, while the bromolactonizations using N-bromosuccinimide and anodic oxidation were found to furnish the six-membered lactone. Using these regiospecific lactonization reactions as a key step, antiallergic and antimicrobial isocoumarins and the benzylidenephthalides thunberginols A and F and their 3'-deoxyanalogs were synthesized from phyllodulcin and hydrangenol. Two phthalides called hydramacrophyllols A and B were isolated from Hydrangeae Dulcis Folium and their stereostructures were determined on the basis of physicochemical and chemical evidence, which included the syntheses of hydramacrophyllols A and B from hydrangenol by the application of the lactonization method using copper(II) chloride. In addition, hydramacrophyllols A and B were found to exhibit an inhibitory effect on the histamine release from rat peritoneal exudate cells induced by antigen- antibody reaction.
- Yoshikawa, Masayuki,Shimada, Hiromi,Yagi, Nobuhiro,Murakami, Nobutoshi,Shimoda, Hiroshi,Yamahara, Johji,Matsuda, Hisashi
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p. 1890 - 1898
(2007/10/03)
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- Chemical transformation from dihydroisocoumarin into benzylidene-phthalide by use of regiospecific oxidative lactonization mediated by copper chloride (H) - Syntheses of thunberginol F and hydramacrophyllol A and B
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Oxidative lactonization of 2-carboxystilbene mediated by CuCl2 proceeded regiospecifically to give the five-membered lactone. By utilizing this lactonization as a key reaction, chemical transformation from dihydroisocoumarine into benzylideneph
- Yoshikawa,Harada,Yagi,Okuno,Muraoka,Koyama,Murakami
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p. 721 - 723
(2007/10/02)
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- Synthesis of 3-substituted isocoumarins and related natural products
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Several N,N-diethyl-2-acylmethylbenzamides (6) were prepared from N,N- diethyl-2-toluamides (4), and the ketoamides (6) were easily cyclized to the corresponding 3-substituted isocoumarins (8) by heating in acetic acid or xylene. This simple procedure was
- Ohta,Kamata,Inagaki,Masuda,Yamamoto,Yamashita,Kawasaki
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p. 1188 - 1190
(2007/10/02)
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- Thunberginols A, B, and F, new antiallergic and antimicrobial principles from hydrangeae dulcis folium.
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Six new antiallergic and antimicrobial principles, thunberginols A, B, C, D, E, and F, were isolated from Hydrangeae Dulcis Folium, the fermented and dried leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO. The chemical structures of thunberginols A, B, and F have been determined on the basis of chemical and physiocochemical evidence. Thunberginols A, B, and F showed more potent antiallergic activity than phyllodulcin, hydrangenol, and AA-861 in the in vitro test using the Schults-Dale reaction in sensitized guinea pig bronchial muscle. Thunberginols A, B, and F also exhibited antimicrobial activity against oral bacteria.
- Yoshikawa,Uchida,Chatani,Murakami,Yamahara
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p. 3121 - 3123
(2007/10/02)
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