6515-31-7Relevant academic research and scientific papers
Flavonoid epoxides. Part 20. Some unusual reactions of dimethyldioxirane (DMD) with flavonoid compounds
Burke, Anthony J.,O'Sullivan, W. Ivo
, p. 8491 - 8500 (2007/10/03)
Dimethyldioxirane (DMD), generally as a solution in acetone, has proved itself to be an excellent epoxidising agent. It was observed that either the 2'-hydroxychalcone epoxide or the tans-2,3-dihydroflavonol could be obtained depending on the pH of the reaction mixture and the type of β-arene ring present in the substrate. Using this methodology trans-2,3-dihydroflavonols can be synthesised in far better yields than by the most commonly used method for their synthesis, that of the Algar-Flynn-Oyamada reaction. Treatment of both flavonol 14 and the novel isoaurone 21 with DMD gave unusual products instead of the expected epoxides, but nonetheless, an epoxide was assumed to have formed during the reaction.
Synthesis and cyclization of 1-(2-hydroxyphenyl)-2-propen-1-one epoxides: 3-Hydroxychromanones and -flavanones versus 2-(1-hydroxyalkyl)-3-coumaranones
Patonay, Tamas,Levai, Albert,Nemes, Csaba,Timar, Tibor,Toth, Gabor,Adam, Waldemar
, p. 5375 - 5383 (2007/10/03)
Competitive α and β cyclization of 2'-hydroxychalcone epoxides affords 2-(α-hydroxybenzyl)-3-coumaranone and/or 3-hydroxyflavanones, which depends on the conditions employed. Epoxidation of 2'-hydroxychalcones by dimethyldioxirane followed by either base- or acid-catalyzed ring closure provides a novel, general, and efficient method for the synthesis of trans-3-hydroxyflavanones, which includes also the naturally occurring derivatives. Extension of this two-step procedure to 1-(2-hydroxyphenyl)-2-alken-1-ones was also accomplished. A strong preference for α cyclization was observed in the case of β-unsubstituted or -monoalkylated α,β-enones, while both 2,2-dimethyl-3-hydroxychromanones and 2-(1-hydroxy-1-methylethyl)-3-coumaranones were obtained from the β,β-dimethylated substrates.
A convenient and general synthesis of trans-3-hydroxyflavanones from chalcones by dimethyldioxirane epoxidation and subsequent base-catalyzed cyclization
Patonay,Toth,Adam
, p. 5055 - 5058 (2007/10/02)
2'-Hydroxychalcone epoxides were found to give trans-3-hydroxyflavanone and 2-(α-hydroxybenzyl)-3-coumaranone under basic conditions. Epoxidation of 2'-hydroxychalcones with dimethyldioxirane followed by treatment of tetrabutylammonium hydroxide provides a convenient and general method for the synthesis of trans-3-hydroxyflavanones.
Hypervalent iodine oxidation of 2'-hydroxychalcones: Synthesis of cis-3-hydroxyflavanones
Prakash, Om,Pahuja, Saroj,Sawhney, Shanti N
, p. 1023 - 1027 (2007/10/02)
Oxidation of 2'-hydroxychalcones (1a-h) using C6H5I(OAC)2-KOH/MeOH leads to the formation of cis-3-hydroxyflavanone dimethylacetals (2a-h).Mild acid hydrolysis (50percent AcOH) of 2a-h affords cis-3-hydroxyflavanones (3a-h) in good yields.Oxidation of cha
Heterocycles. XX. Reactions of 2''-Methoxymethoxychalcone Epoxides under Acidic Conditions
Takahashi, Hiroshi,Kubota, Yumiko,Fang, Lin,Li, Shaoshun,Onda, Masayuki
, p. 4597 - 4604 (2007/10/02)
The effect of substituents on the formation of products in the reactions of 2''-methoxymethoxychalcone epoxides under acidic conditions has been examined.Regardless of the 6''-substituent, the presence of a 4'-hydroxyl group results in the exlusive format
