109873-38-3Relevant academic research and scientific papers
General approach to anthrapyran antibiotics exemplified by the synthesis of rac-γ-indomycinone
Krohn, Karsten,Tran-Thien, Hoan Trang,Ahmed, Ishtiaq
supporting information; experimental part, p. 2223 - 2225 (2011/06/20)
A new general route to the anthrapyran antibiotics is presented, which allows the attachment of various branched side chains. A key step is the Baker-Venkataraman rearrangement of the propionate 9 to the diketone 10. Acid-catalyzed cyclization gives the ethyl-branched anthrapyranone 11, serving as the starting material for further side-chain elongation. For example, the ethyl-substituted anthrapyranones 12a,b,c, the corresponding bromides 13b,c, the phosphonium salts 14b,c, the olefins 22a,c, and the epoxides 23a,c are prepared by starting from 11. A first example demonstrating the potential of this route is the synthesis of the naturally occurring γ-indomycinone (24b), prepared bycuprate-mediated opening of the epoxide 23a. A general route to the anthrapyran antibiotics is presented, which allows the attachment of various branched side chains. In a first example, an ethyl-branched anthrapyranone, prepared in a Baker-Venkataraman rearrangement, was used to obtain a 1-methylvinyl-substituted anthrapyranone that was transformed into rac-indomycinone via an intermediate epoxide in a cuprate-mediated epoxide opening. Copyright
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.
SYNTHETIC STUDIES ON NOGALAMYCIN CONGENERS ; SYNTHESES AND ANTITUMOR ACTIVITY OF VARIOUS NOGALAMYCIN CONGENERS
Matsuda, Fuyuhiko,Kawasaki, Motoji,Ohsaki, Masako,Yamada, Kaoru,Terashima, Shiro
, p. 5745 - 5760 (2007/10/02)
Various structural types of nogalamycin congeners and their partial structures, which had been previously synthesized in the course of our synthetic studies on the total syntheses or were originally produced by employing the explored synthetic scheme, were subjected to in vitro cytotoxicity and in vivo antitumor activity assay against P388 murine leukemia.These studies obviously disclosed novel aspects of the structure-activity relationships of nogalamycin congeners.
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.
