Facile synthesis of polyhydroxycoumaronochromones with quinones: synthesis of alkylpolyhydroxy-and alkoxycoumaronochromones from 2'-hydroxyisoflavones

摘要

4',5,7-Trihydroxy-or 8-alkyl-4',5,7-trihydroxycoumaronochormones were synthesized by oxidative cyclization of the corresponding 2'-hydroxyisoflavones with o-chloranil under mild conditions. By contrast, alkoxycoumaronochormones were synthesized by oxidative cyclization of the corresponding 2'-hydroxyisoflavones with DDQ.