The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform
Takeaki Naito - One of the best experts on this subject based on the ideXlab platform.
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a convenient route to the Furopyran core of dysiherbaine
Organic and Biomolecular Chemistry, 2003Co-Authors: Okiko Miyata, Ryuichi Iba, Jun Hashimoto, Takeaki NaitoAbstract:The bicyclic core, furo[3,2-b]pyran, of the dysiherbaines has been synthesized via two routes involving the imino 1,2-Wittig rearrangement of allyl furohydroximate and the asymmetric dihydroxylation of furylpropenol derivative.
Maosheng Cheng - One of the best experts on this subject based on the ideXlab platform.
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gold i catalyzed angle strain controlled strategy to Furopyran derivatives from propargyl vinyl ethers insight into the regioselectivity of cycloisomerization
ChemInform, 2016Co-Authors: Shengfei Jin, Chongguo Jiang, Xiaoshi Peng, Chunhui Shan, Shanshan Cui, Yuanyuan Niu, Yang Liu, Yu Lan, Yongxiang Liu, Maosheng ChengAbstract:A unique strategy for the regiospecific synthesis of bicyclic Furopyran derivatives has been developed via a gold(I)-catalyzed propargyl-Claisen rearrangement/6-endo-trig cyclization of propargyl vinyl ethers. The introduction of angle strain into the substrates significantly altered the reaction’s regioselectivity. Insight into the regioselectivity of the cycloisomerization was obtained with density functional theory calculations.
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a gold i catalyzed substituent controlled cycloisomerization of propargyl vinyl ethers to multi substituted furofuran and Furopyran derivatives
Chemical Communications, 2016Co-Authors: Yongxiang Liu, Shengfei Jin, Xiaoshi Peng, Shanshan Cui, Yuanyuan Niu, Yanshi Wang, Maosheng ChengAbstract:A gold(I)-catalyzed substituent-controlled strategy for the stereoselective synthesis of bicyclic furan and pyran derivatives has been developed. The mechanisms of the reactions have been studied thoroughly by deuterium labelling experiments. The applications of the methodologies were demonstrated by evaluating the preliminary anti-fungal activity of the synthetic compounds.
Okiko Miyata - One of the best experts on this subject based on the ideXlab platform.
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a convenient route to the Furopyran core of dysiherbaine
Organic and Biomolecular Chemistry, 2003Co-Authors: Okiko Miyata, Ryuichi Iba, Jun Hashimoto, Takeaki NaitoAbstract:The bicyclic core, furo[3,2-b]pyran, of the dysiherbaines has been synthesized via two routes involving the imino 1,2-Wittig rearrangement of allyl furohydroximate and the asymmetric dihydroxylation of furylpropenol derivative.
Hideyuki Sugimura - One of the best experts on this subject based on the ideXlab platform.
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stereoselective synthesis of the dysiherbaine Furopyran core via bf3 promoted formal 3 2 annulation of aldehydo aldoses with allylsilanes
Tetrahedron Letters, 2016Co-Authors: Koki Hotoda, Asami Ohnuma, Kosuke Kusakabe, Aki Tanaka, Ikuo Sasaki, Hideyuki SugimuraAbstract:A highly stereoselective synthesis of the hexahydrofuro[3,2-b]pyran core of (−)-dysiherbaine is described. The key step in this synthesis includes the stereocontrolled formation of the tetrahydrofuran ring using the formal [3+2] annulation of the isopropylidene-protected aldehydo-L-arabinose and the β-substituted allylsilane mediated by trifluoroborane etherate.
Antonio Evidente - One of the best experts on this subject based on the ideXlab platform.
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phytotoxins produced by phoma chenopodiicola a fungal pathogen of chenopodium album
Phytochemistry, 2015Co-Authors: Marco Evidente, Alessio Cimmino, Maria Chiara Zonno, Maurizio Vurro, Marco Masi, Alexander Berestetskyi, Ernesto Santoro, Stefano Superchi, Antonio EvidenteAbstract:Abstract Two phytotoxins were isolated from the liquid culture of Phoma chenopodiicola , a fungal pathogen proposed for the biological control of Chenopodium album , a common worldwide weed of arable crops. The two phytotoxins appeared to be a new tetrasubstituted Furopyran and a new ent- pimaradiene. From the same culture a new tetrasubstituted isocoumarin was also isolated. These compounds were characterized by using spectroscopic (essentially 1D and 2D NMR and HR ESI MS) and chemical methods as 3-(3-methoxy-2,6-dimethyl-7a H -furo[2,3- b ]pyran-4-yl)-but-2-en-1-ol (chenopodolan D, 1 ) (1 S ,2 S ,3 S ,4 S ,5 S ,9 R ,10 S ,12 S ,13 S )-1,3,12-triacetoxy-2,hydroxy-6-oxo- ent -pimara-7(8),15-dien-18-oic acid 2,18-lactone (chenopodolin B, 3 ), and, 4,5,7-trihydroxy-3-methyl-isochroman-1-one (chenisocoumarin, 2 ) The absolute configuration of chenisocoumarin was assigned by applying an advanced Mosher’s method through the derivatization of its secondary hydroxylated carbon C-4, while that of chenopodolan D by application of quantum mechanical calculations of chiroptical (ECD and ORD) properties. When assayed by leaf puncture against non-host weeds, chenopodolan D and chenopodolin B showed phytotoxicity while chenisocoumarin and the 9- O -acetyl derivative of chenopodolan D were inactive. These results confirm that the nature of the side chain at C-4 in chenopodolans, and in particular its hydroxylation, are important features for activity. The activity of chenopodolin B could also be explained by its possible hydrolysis to chenopodolin.
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chenopodolans a c phytotoxic Furopyrans produced by phoma chenopodiicola a fungal pathogen of chenopodium album
Phytochemistry, 2013Co-Authors: Alessio Cimmino, Anna Andolfi, Maria Chiara Zonno, Fabiana Avolio, Alexander Berestetskiy, Maurizio Vurro, Antonio EvidenteAbstract:Abstract Three tetrasubstituted Furopyrans, named chenopodolans A–C, were isolated together with the well known fungal metabolite (−)-( R )-6-hydroxymellein from the liquid culture of Phoma chenopodiicola , a fungal pathogen proposed for the biological control of Chenopodium album , a common worldwide weed of arable crops. The structures of chenopodolans A–C were established by spectroscopic and chemical methods as 2-(3-methoxy-2,6-dimethyl-7a H -furo[2,3- b ]pyran-4-yl)-butane-2,3-diol, 1-(3-methoxy-2,6-dimethyl-7a H -furo[2,3- b ]pyran-4-yl)ethanol and 3-methoxy-2,6-dimethyl-4-(1-methylpropenyl)-7a H -furo[2,3- b ]pyran, respectively. The absolute configuration R to the hydroxylated secondary carbon (C-11) of the side chain at C-4 of chenopodolan A was determined by applying an advanced Mosher’s method. Assayed by leaf puncture on host and non-host weeds chenopodolans A and B, and the 11- O -acetylchenopodolan A showed a strong phytotoxicity. These results showed that the nature of the side chain attached to C-4 is an important feature for the phytotoxicity. A weak zootoxic activity was only showed by chenopodolan B.
