10064-08-1Relevant academic research and scientific papers
Ru(III)-Catalyzed Cyclization of Arene-Alkene Substrates via Intramolecular Electrophilic Hydroarylation
Youn, So Won,Pastine, Stefan J.,Sames, Dalibor
, p. 581 - 584 (2007/10/03)
(Matrix presented) We herein report that RuCl3/AgOTf has proven to be a hydroarylation catalyst with an efficiency and scope superior to previously known methods. This catalyst demonstrated consistent performance with arene-ene substrates of diverse structural features, providing good to excellent yields of cyclization products (chromanes, tetralins, terpenoids, dihydrocoumarins).
Enantio- and diastereoselective stepwise cyclization of polyprenoids induced by chiral and achiral LBAs. A new entry to (-)-ambrox, (+)-podocarpa-8,11,13-triene diterpenoids, and (-)-tetracyclic polyprenoid of sedimentary origin
Ishihara, Kazuaki,Ishibashi, Hideaki,Yamamoto, Hisashi
, p. 3647 - 3655 (2007/10/03)
An enantio- and diastereoselective stepwise cyclization of polyprenoids induced by Lewis acid-assisted chiral Bronsted acids (chiral LBAs) and achiral LBAs is described. In particular, the absolute stereocontrol in the initial cyclization of polyprenoids to form an A-ring induced by chiral LBAs and the importance of the nucleophilicity of the internal terminator in polyprenoids for the relative stereocontrol in subsequent cyclization are demonstrated. (-)-Ambrox was synthesized via the enantioselective cyclization of (E,E)-homofarnesyl triethyrsily ether with triethylsilyl ether with tin(IV) chloride-coordinated (R)-2-(o-fluorobenzyloxy)-2′-hydroxy-1,1′-binaphthyl ((R)-BINOL-o-FBn) and subsequent diastereoselective cyclization with CF3CO2H·SnCl4 as key steps. Protection of (E,E)-homofarnesol by a triethylsilyl group increased the enantioselectivity of chiral LBA-induced cyclization and both the chemical yield and diastereoselectivity in the subsequent cyclization. The enantioselective cyclization of homo(polyprenyl)arenes possessing an aryl group was also induced by (R)-BINOL-o-FBn·SnCl4. Several optically active podocarpa-8,11,13-triene diterpenoids and (-)-tetracyclic polyprenoid of sedimentary origin were synthesized (75-80% ee) by the enantioselective cyclization of homo(polyprenyl)benzene derivatives induced by (R)-BINOL-o-FBn·SnCl4 and subsequent diastereoselective cyclization induced by BF3-Et2O/EtNO2 or CF3CO2H·SnCl4.
Synthesis of (+)- and (-)-ferruginol via asymmetric cyclization of a polyene
Tada, Masahiro,Nishiiri, Sei,Zhixiang, Yang,Imai, Yumiko,Tajima, Shiho,Okazaki, Naoko,Kitano, Yoshikazu,Chiba, Kazuhiro
, p. 2657 - 2664 (2007/10/03)
Stereoselectivity of modified polyenes which have a terminal benzene ring was found to be dependent on the size of substituent on the adjacent asymmetric carbon to the terminal benzene ring of the polyenes. (R)-(+)-2′-Hydroxy-1,1′-binaphthyl-2-yl(2R)-2-(4-methoxyphenyl)-5,9- dimethyldeca-4,8-dienoate gave(R)-(+)-2′-hydroxy-1,1′-binaphthyl-2-yl (4aS,9 R, 10aS)-1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-trimethylphenanthene-9- carboxylate stereoselectively by treatment with BF3-Et2O in nitromethane. The products were elaborated to (+)-ferruginol 1. (-)-Ferruginol 2 and (±)-ferruginol 3 were also synthesized via a similar synthetic route. The Royal Society of Chemistry 2000.
Stereoselective synthesis of (+)-ferruginyl methyl ether and (+)-sugiyl methyl ether
Yonghong, Gan,Xinfu, Pan
, p. 130 - 132 (2007/10/03)
A facile stereoselective synthetic procedure to (+)-ferruginyl methyl ether and (+)-sugiyl methyl ether has been developed with high stereoselectivity and overall yield.
Stereoselective synthesis of (-)-6,7-dehydroferruginyl methyl ether
Gan, Yonghong,Li, Anpai,Pan, Xinfu,Chan, Albert S. C.,Yang, Teng-Kuei
, p. 781 - 787 (2007/10/03)
A stereoselective synthetic route to (-)-6,7-dehydroferruginyl methyl ether was developed from (S)-(-)-α-cyclocitral. Copyright (C) 2000 Elsevier Science Ltd.
Stereoselective intramolecular 6-exo-Heck reaction : A facile synthetic route to podocarpa-8,11,13-triene and diterpenoid resin acids intermediates
Mukhopadhyaya, Jayanta K.,Ghosh, Ajit K.,Ghatak, Usha Ranjan
, p. 835 - 837 (2007/10/03)
Intramolecular Heck reaction of the olefins 1a-c in the presence of sodium formate affords ca 3:1 mixtures of the respective trans- and cis-octahydrophenanthrenes 3a-c and 4a-c. Similar reaction of the olefmic ester 2 provides a 70:30 mixture of (±)-methyl desisopropyldehydroabietate 6 and (±)10-epi-methyl desoxypodocarpate 7.
Diterpene Synthesis. Part 2. Acid-catalysed Cyclisation of p-Methoxyphenylethyltrimethylcyclohexanols
Axon, Barry W.,Davis, Brian R.,Woodgate, Paul D.
, p. 2956 - 2962 (2007/10/02)
The acid-catalysed reactions of two phenylethylcyclohexanols, precursors to tricyclic diterpenoids, are reported.The reaction produced both a bicyclic alkene and a tricyclic molecule; the former was converted into the latter in protic media.Conditions for
