Isolation and synthesis of two coumarins from melampodium divaricatum

Abstract

Two new coumarin isomers have been isolated from Melampodium divaricatum and identified by spectral procedures as 8-hydroxy-7-(3′-methyl-2′-butenyloxy)coumarin ( 1) and 7-hydroxy-8-(3′-methyl-2′-butenyloxy)coumarin ( 2). The regioselective synthesis of each isomer was made by two different alkylation pathways confirming their structures.