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Search for "quinone" in Full Text gives 130 result(s) in Beilstein Journal of Organic Chemistry.

Mitomycins syntheses: a recent update

  • Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

Graphical Abstract
  • the p-quinone are called mitosanes or mitosenes depending whether they are at the oxidation state of an indoline (Y1 or Y2 = H) or an indole (Y1 = Y2 = C=C). Compounds bearing an aziridine at C1 and C2 are described specifically as aziridinomitosanes and aziridinomitosenes respectively. Compounds
  • possessing a hydroquinone (protected or not) in place of the original quinone are identified by inclusion of the prefix leuco in reference to the Greek word leukos (clear, white) and the lack of intense color usually specific of the corresponding quinone ring. The mitomycins A and C differ only by the
  • substituents on the quinone ring and transformation from 6 to 7 is realized by simple treatment with ammonia [23][24]. The mitomycins F, 8, and porfiromycin, 9, are synthesized by methylation of the aziridine of mitomycin A and mitomycin C, respectively. Mitomycin G, 12, mitomycin H, 13, and mitomycin K, 14
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Review
Published 08 Jul 2009

Diels- Alder reactions using 4,7-dioxygenated indanones as dienophiles for regioselective construction of oxygenated 2,3-dihydrobenz[f]indenone skeleton

  • Natsuno Etomi,
  • Takuya Kumamoto,
  • Waka Nakanishi and
  • Tsutomu Ishikawa

Beilstein J. Org. Chem. 2008, 4, No. 15, doi:10.3762/bjoc.4.15

Graphical Abstract
  • B; quinone route) [28]; 2) regioselective ring-opening of 5,8-epoxy-2,3-dihydrobenz[f]indenone 11 derived from benzyne 10 and furan (9) (path C, benzyne route). Now we report that both of the methods are effective for the construction of the 2,3-dihydrobenz[f]indenone skeleton, but not for the
  • regioselective synthesis of the desired 4,8,9-trioxygenated ones. Results and Discussion In the quinone route, we designed several indanetriones to modulate steric and electronic factors; i.e. 1,4,7-indanetrione 8, the 6-brominated quinone 12, and the corresponding 4-monoacetals 13 and 14 (Scheme 2
  • regioselectivity was not affected in the reaction in the presence of a catalytic amount of BF3 · OEt2 (entry 7). We next turned to the use of quinone monoacetals 13 and 14 as dienophiles [36]. No adduct was formed on reaction of 13 in CH2Cl2 without a catalyst at room temperature (rt) (entry 8), whereas refluxing
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Full Research Paper
Published 15 May 2008

Variations in product in reactions of naphthoquinone with primary amines

  • Marjit W. Singh,
  • Anirban Karmakar,
  • Nilotpal Barooah and
  • Jubaraj B. Baruah

Beilstein J. Org. Chem. 2007, 3, No. 10, doi:10.1186/1860-5397-3-10

Graphical Abstract
  • have anion binding ability on protonation or have complex forming ability with metals. The incorporation of pyridine ring to a quinone has also another facet as we have recently observed that in picolyl derivative of 1,8-naphthalimides the π-π interactions are governed by the position of the nitrogen
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Preliminary Communication
Published 01 Mar 2007

Effect of transannular interaction on the redox- potentials in a series of bicyclic quinones

  • Grigoriy Sereda,
  • Jesse Van Heukelom,
  • Miles Koppang,
  • Sudha Ramreddy and
  • Nicole Collins

Beilstein J. Org. Chem. 2006, 2, No. 26, doi:10.1186/1860-5397-2-26

Graphical Abstract
  • the triptycene-quinone system selectively destabilize the product of the two-electron reduction. Conclusion We have shown that first redox-potentials of substituted bicyclic quinones correlate with their calculated LUMO energies and the energies of reduction. The second redox-potentials correlate with
  • calculated LUMO+1 energies. As opposed to the LUMO orbitals, the LUMO+1 orbital coefficients are weighted significantly on the non-quinone part of the bicyclic system. This accounts for: (1) significantly larger substituent effect on the second redox-potentials, than on the first redox-potentials; (2) lack
  • of stability of the product of two electron reduction of 5,8-diacetoxy-9,10-dihydro-9,10-[1,2]benzenoanthracene-1,4-dione 5. Background It has been shown that 9,10-dihydro-9,10-[1,2]benzenoanthracene-1,4-dione (triptycene-quinone, 1) exhibits anti-leukemia activity, comparable with activity of
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Published 08 Dec 2006

Total syntheses of oxygenated brazanquinones via regioselective homologous anionic Fries rearrangement of benzylic O-carbamates

  • Glaucia Barbosa Candido Alves Slana,
  • Mariângela Soares de Azevedo,
  • Rosângela Sabattini Capella Lopes,
  • Cláudio Cerqueira Lopes and
  • Jari Nobrega Cardoso

Beilstein J. Org. Chem. 2006, 2, No. 1, doi:10.1186/1860-5397-2-1

Graphical Abstract
  • condensed aromatics. We found this route very attractive and envisaged that by in situ treatment of intermediate 4 with the third equivalent of sec-BuLi, the cyclization to the desired quinone 1a-d would be obtained. One unexpected result was the formation of the phthalide 9 when the dimethoxy carbamate 2d
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Published 21 Feb 2006
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