Synthesis and Cyclization of 1-(2-Hydroxyphenyl)-2-propen-1-one Epoxides:  3-Hydroxychromanones and -flavanones versus 2-(1-Hydroxyalkyl)-3-coumaranones

Abstract

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.

Metal–organic frameworks as solid catalysts for the synthesis of nitrogen-containing heterocycles

“…Chalcones are versatile key precursors for the synthesis of many heterocyclic compounds that can exhibit biological or therapeutic activity. 53,54 On the other hand, pyrimidines exhibit diverse pharmacological properties as effective bactericides, fungicides, viricides and insecticides. [55][56][57][58][59][60][61][62][63][64] Pyrimidines and annulated pyrimidine derivatives are also known to display anticancer, antimalarial, antileshmanial and antifilarial activity.…”

Microwave Induced Improved Synthesis of Some Novel Substituted 1, 3‐Diarylpropenones and their Antimicrobial Activity

“…The presence of reactive α, β-unsaturated keto group in the 1,3 diarylpropeneones is found to be responsible for their biological activity. In addition, these compounds are of a great interest due to their use as starting material in the synthesis of a series of a heterocyclic 9 , carbocyclic 10 and flavonoids 11 . Moreover these are important intermediates in many addition reactions of nucleophiles due to inductive polarization of carbonyl group at the β-position.…”

Syntheses of β,β-Diarylvinyl Phenyl Ketones by Benzotriazole-Mediated Tandem Coupling-Elimination

“…β,β-Diarylvinyl phenyl ketones are frequently observed in natural products and are widely used versatile organic synthons; for example, (i) they can be epoxidized , and then converted into cumarones and flavones, (ii) they can be added to aromatics to give polyaryl substituted ketones, or (iii) they can be simply hydrogenated to give ketones …”