14796-31-7Relevant 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 (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.
Kinetics and Mechanism of the Cyclisation of Some 2'-Hydroxychalcone Epoxides and Subsequent Elimination Reactions of Aurone Hydrates
Adams, Christopher J.,Main, Lyndsay
, p. 9929 - 9938 (2007/10/02)
Analysis of the pH-rate profile for the cyclisation of the monoanion of 2'-hydroxychalcone epoxide which gives 3-hydroxyflavanone and of some 6'-alkoxy-substituted analogues which give mostly aurone hydrate, gives rate coefficients which quantify the preference for α over β cyclisation when 6'-substituents are present.These are considered in terms of stereoelectronic factors which may be responsible for the preference.Also reported are rate coefficients for the subsequent reaction of aurone hydrates in which aurones and coumaranones are formed.
