6-Prenyloxy-7-methoxycoumarin, a coumarin-hemiterpene ether from Carduus tenuiflorus
Abstract From the acetone extract of Carduus tenuiflorus , a new coumarin-hemiterpene ether was isolated, which was identified as 6-(3,3-dimethylallyloxy)-7-methoxycoumarin. The synthesis of this coumarin and that of its positional isomer 7-(3,3-dimethylallyloxy)-6-methoxycoumarin were carried out from esculetin. Two other coumarins, three lignans and three flavonoids were also isolated.