7,20-Diisocyanoadociane, a scarce marine metabolite with potent antimalarial activity, was synthesized as a single enantiomer in 13 steps from simple building blocks (17 linear steps). Chemical synthesis enabled identification of isocyanoterpene antiplasmodial activity against liver-stage parasites, which suggested that inhibition of heme detoxification does not exclusively underlie the mechanism of action of this class.