Synthesis of labelled dihydroartemisinic acid

[15-13C2H3]-Dihydroartemisinic acid (), [15-C2H3]-dihydroartemisinic acid () and [15-13CH3]-dihydroartemisinic acid () have been obtained in good yield and high isotopic enrichment by a reconstructive synthesis from artemisinin. These labelled compounds were designed to be used in biosynthetic experiments to determine the origins of artemisinin and other sesquiterpene natural products from Artemisia annua.