Synthesis of Geranyloxycoumarin Derivatives under Mild Conditions Using Cs2CO3

Abstract

In this study, the synthesis of various geranyloxycoumarin derivatives from hydroxycoumarin was obtained in good yield under mild conditions using Cs2CO3. In the synthesis of geranyloxycoumarin derivatives, when 4-hydroxycoumarin reacts with geranyl bromide under mild conditions due to tautomeric keto-enol forms, 4-geranyoxycoumarin (3a), C-alkylated coumarin (3aa) and structure 3ab formed by hydrolysis and decarboxylation from 3aa were formed products. In addition, the alkylation reaction of 3-OH, 5-OH, 6-OH, 7-OH, and 8-OH coumarin except 4-OH group produced a high yield.