Laccase-catalyzed domino reactions of 4-hydroxy-6-methyl-2H-pyran-2-one or substituted 4-hydroxy-2H-chromen-2-ones with catechols using molecular oxygen as an oxidant afford coumestans and related O-heterocycles with yields ranging from 51% to 99%.
The present invention relates to derivatives of the 1H-pyrano[4,3-b]benzofuran-1-one structure and their nitrogen analogues which possess powerful antioxidant properties combined with a highly effective UV absorbing functionality in one molecule. These compounds are especially useful in cosmetical and dermatological formulations.
Electrochemical oxidation of catechols in the presence of 4-hydroxy-6-methyl-2-pyrone
作者:Davood Nematollahi、Zinat Forooghi
DOI:10.1016/s0040-4020(02)00422-2
日期:2002.6
Electrochemicaloxidation of catechols (1a–1c) has been studied in the presence of 4-hydroxy-6-methyl-2-pyrone (3) as nucleophile in aqueous solution, using cyclic voltammetry and controlled-potential coulometry. The results indicate that the quinones derived from catechols (1a–1c) participate in Michael addition reactions with 3 to form the corresponding heterocyclic compounds (6a–6c). In this work