129878-46-2Relevant academic research and scientific papers
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 (1996)
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.
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.
Dioxirane Epoxidation of α,β-Unsaturated Ketones
Adam, Waldemar,Hadjiarapoglou, Lazaros,Smerz, Alex
, p. 227 - 232 (2007/10/02)
The synthesis of epoxides 3a-r is achieved in excellent yields by reaction of the α,β-unsaturated ketones 1a-c, 4,4'-disubstituted (E)-chalcones 1d-o, and 2'-hydroxy-4-substituted (E)-chalcones 1p-r with isolated dimethyldioxirane (2a) (as acetone solution) and/or in situ generated ethyl(methyl)dioxirane (2b).This method constitutes a useful alternative to the Weitz-Scheffer epoxidation (alkaline H2O2) of such electron-poor substrates.Key Words: Epoxidation / Dioxiranes / Ketones, α,β-unsatured / (E)-Chalcones / (E)-2'-Hydroxychalcones / 2-Cycloen-1-ones / Caroate
