6512-26-1Relevant academic research and scientific papers
Total Synthesis of Premithramycinone H and Related Anthrapyran Antibiotics
Krohn, Karsten,Vitz, Juergen
, p. 209 - 219 (2007/10/03)
Two approaches are described for the preparation of 2-(1',3'-dioxoalkyl)-substituted 1-hydroxyanthraquinones 10a-d and 20a-c, which were cyclized in a biomimetic-type reaction to the anthra[1,2-b]pyran skeletons 11a-d and 21a-c of the heydamcin- or pluram
An anionic polycondensation strategy for the synthesis of dibenzoxanthenones: Progress toward the synthesis of hypoxyxylerone
Chevenier, Emmanuel,Lucatelli, Christophe,Pandya, Urvish,Wang, Wei,Gimbert, Yves,Greene, Andrew E.
, p. 2693 - 2696 (2007/10/03)
An anionic polycondensation has been used as the key step in a highly convergent strategy for the preparation of hypoxyxylerone derivatives.
Process for the manufacture of hypoxyxylerone derivatives
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, (2008/06/13)
The present invention relates to the total synthesis of hypoxyxylerone derivatives (formula I) and their biological activities. R1-R5 are as described in the description.
Total synthesis of (S)-(+)-citreofuran by ring closing alkyne metathesis
Fuerstner, Alois,Castanet, Anne-Sophie,Radkowski, Karin,Lehmann, Christian W.
, p. 1521 - 1528 (2007/10/03)
A concise total synthesis of citreofuran 4 is described, a structurally unique octaketide derivative belonging to the curvularin family. Key steps involve the elaboration of orsellinic acid methyl ester 5 to acid 14, which converts, on attempted formation of the corresponding acid chloride, to the 3-alkoxyisocoumarin derivative 20. This heterocycle can be used as an activated ester to give ketone 21 on treatment with 3-pentynylmagnesium bromide in the presence of TMSCl as the activating agent. Ring-closing alkyne metathesis (RCAM) of diyne 21 catalyzed by (tBuO)3W≡CCMe3 affords the strained cycloalkyne 22. Treatment with acid renders its triple bond susceptible to nucleophilic attack by the adjacent carbonyl group, thus leading to a transannular cycloaromatization with formation of the intact skeleton of citreofuran. An X-ray crystallographic study reveals conformational details about this natural product. Finally, it is shown that 4 as well as its protected precursor 23 are able to cleave double-stranded DNA under oxidative conditions.
Synthesis of homophthalates from allenic diesters: Conversion into viocristin and analogues, and application to 6-methylpretetramid
Caliskan, Ece,Cameron, Donald W.,Griffiths, Peter G.
, p. 1013 - 1020 (2007/10/03)
Oxy-substituted homophthalic anhydrides have been synthesized by cycloaddition of di- and tri-oxy butadienes to the allenic diester (1). By base-catalysed cycloaddition to appropriate benzoquinones they have afforded new syntheses of viocristin (19), isov
A Synthesis of Polycyclic Aromatic Compounds by the Ca(OAc)2-Induced Aromatization of Polyoxoalkanedioates Generated from Diesters and Acetoacetate Dianion
Yamaguchi, Masahiko,Hasebe, Koichi,Higashi, Hirofumi,Uchida, Minoru,Irie, Akemi,Minami, Toru
, p. 1611 - 1623 (2007/10/02)
The dual-Claisen condensation of diesters with acetoacetate dianion generated tetraoxoalkanedioates, whose aromatization by Ca(OAc)2-promoted intramolecular condensation constructed two carbocyclic rings containing phenol part.The reactions converted glutarates to bicyclic phenols and homophthalates to 1,9-dihydroxyanthracenes.The latters were air-oxidized to anthraquinones in the presence of K2CO3.The regiochemistry of the arene synthesis was studied.As the products of this synthesis also were glutarates, further extension of the aromatic ring system was carried out.Pentacenequinones were synthesized from anthracenes, while anthraquinones gave naphthacenequinones.The reactions are related to the biosynthesis of polycyclic aromatic compounds, and arenes obtained are useful intermediates in the natural products synthesis.A formal synthesis of aklavinone was achieved.
Biosyntheses of Antibiotic A26771B by Penicillium turbatum and Dehydrocurvularin by Alternaria cinerariae: Comparison of Stereochemistry of Polyketide and Fatty Acid Enoyl Thiol Ester Reductases
Arai, Kunizo,Rawlings, Bernard J.,Yoshizawa, Yuko,Vederas, John C.
, p. 3391 - 3399 (2007/10/02)
The biosyntheses of reduced polyketides and fatty acids were compared by use of stable isotope labeling and NMR spectroscopy.Incorporations of sodium -, -, -, -, -, and acetates i
A BIOMIMETIC SYNTHESIS OF POLICYCLIC QUINONES
Yamaguchi, Masahiko,Hasebe, Koichi,Uchida, Minoru,Irie, Akemi,Minami, Toru
, p. 2017 - 2020 (2007/10/02)
Various polycyclic quinones were synthesized by the intramolecular condensation of polyketides followed by the air-oxidation.
A Synthesis of Bikaverin (7,12-Dihydro-6,11-dihydroxy-3,8-dimethoxy-1-methyl-10H-benzoxanthene-7,10,12-trione) and some Related Benzoxanthones and Quinones
Kjaer, Dana,Kjaer, Anders,Risbjerg, Elisabeth
, p. 2815 - 2820 (2007/10/02)
Bikaverin, a biologically interesting fungal pigment with the highly oxidised benzoxanthone structure (1), has been synthesized in two steps from 2-hydroxy-4-methoxy-6-methylacetophenone (6f) and dimethyl 3,5-dimethoxyhomophthalate (7f).The synthesis invo
