Showing papers on "Anthrone published in 2007"
TL;DR: A highly efficient asymmetric Michael addition of anthrone to nitroalkenes catalyzed by cinchona alkaloids was described and up to 99% ee of the corresponding adduct was obtained.
55 citations
1 Jan 2007
TL;DR: In this paper, a highly efficient asymmetric Michael addition of anthrone to nitroalkenes catalyzed by cinchona alkaloids was described, and up to 99% ee of the corresponding adduct was obtained.
Abstract: A highly efficient asymmetric Michael addition of anthrone to nitroalkenes catalyzed by cinchona alkaloids was described. Up to 99% ee of the corresponding adduct was obtained. (c) 2007 Elsevier Ltd. All rights reserved.
3 citations
TL;DR: In this paper, a new route for the synthesis of spiro derivatives anthrone was designed using a Michael addition reaction followed by a Dieckmann condensation and Thorpe-Ziegler cyclisation.
Abstract: Novel routes for the synthesis of spiro derivatives anthrone have been designed using a Michael addition reaction followed by a Dieckmann condensation and Thorpe-Ziegler cyclisation. Bis-Michael addition of pyrazole-5-thione with 1,5-diarylpenta-1,4-dien-3-one gave directly a spiro derivative of pyrazole-5-thione. An enol lactone was synthesised by using mono Michael addition on dimedone, followed by hydrolysis and condensation.
2 citations
TL;DR: In this article, a highly efficient asymmetric Michael addition of anthrone to nitroalkenes catalyzed by cinchona alkaloids was described, and up to 99% ee of the corresponding adduct was obtained.
Abstract: A highly efficient asymmetric Michael addition of anthrone to nitroalkenes catalyzed by cinchona alkaloids was described. Up to 99% ee of the corresponding adduct was obtained.
2 citations
TL;DR: The title compound, C21H13NO4, was prepared by the reaction of anthrone and 4-hydr-oxy-3-nitrobenzaldehyde catalysed by anhydrous hydrogen chloride as mentioned in this paper.
Abstract: The title compound, C21H13NO4, was prepared by the reaction of anthrone and 4-hydroxy-3-nitrobenzaldehyde catalysed by anhydrous hydrogen chloride. In the molecule, the anthraquinone fragment is non-planar; the central six-membered ring adopts an asymmetric boat conformation, while the two outer rings make a dihedral angle of 36.0 (1)°. Weak intermolecular C—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers.
2 citations
Journal Article•
TL;DR: The improved anthrone colorimetry was effective, accurate and stable for determination of poly Saccharide concentration in bulk of Streptococcus pneumoniae polysaccharide conjugate.
Abstract: Objective To establish an improved anthrone colorimetry for the determination of capsular polysaccharide concentration in Streptococcus pneumoniae polysaccharide conjugateMethods Optimize the anthrone concentration and temperature,verify the improved anthrone colorimetry and test for its reproducibilityResults The optimal anthrone concentration and temperature for anthrone colorimetry were 03 g/300 ml and 40℃ respectivelyThe regression coefficient of standard curve for determination of polysaccharide concentration in bulk of Streptococcus pneumoniae polysaccharide conjugate by the improved anthrone colorimetry was highThe method showed good stability and reproducibilityConclusion The improved anthrone colorimetry was effective,accurate and stable for determination of polysaccharide concentration in bulk of Streptococcus pneumoniae polysaccharide conjugate
2 citations
1 citations
TL;DR: In this article, various arylalkanes such as fluorenes, xanthene, anthrone, 9,10-dihydroanthracene, and diphenylmethane are effectively transformed into the corresponding aryls ketones, while amino and aldehyde functionalities remain intact.
Abstract: Various arylalkanes such as fluorenes, xanthene, anthrone, 9,10-dihydroanthracene, and diphenylmethane are effectively transformed into the corresponding aryl ketones, while amino and aldehyde functionalities remain intact, under air in the presence of cesium carbonate.
1 citations
TL;DR: In this article, a non-planar compound, C22H15NO5, prepared from anthrone and 4-hydr-oxy-3-meth-oxy -5-nitro-benzaldehyde, is described.
Abstract: In the title compound, C22H15NO5, prepared from anthrone and 4-hydroxy-3-methoxy-5-nitrobenzaldehyde, the anthracene fragment is non-planar. The central six-membered ring assumes an asymmetric boat conformation, while the two outer benzene rings make a dihedral angle of 28.08 (10)°. The hydroxy group is involved in an intramolecular hydrogen bond. In the crystal structure, a weak intermolecular C—H⋯O hydrogen bond links the molecules into ribbons along the c axis.
1 citations
TL;DR: The six-step synthesis of hypericin by the regioselective two-fold Diels-Alder reaction of 1,4-benzoquinone first with (1methoxy-3-methylbuta-1,3-dienyloxy)trimethylsilane leading to 7-methyljuglo...
Abstract: The six-step synthesis of hypericin by the regioselective two-fold Diels-Alder reaction of 1,4-benzoquinone first with (1-methoxy-3-methylbuta-1,3-dienyloxy)trimethylsilane leading to 7-methyljuglo...