Malaria is the world's most important tropical parasitic disease and there are an estimated 300–500 million cases of malaria each year. The emergence of multi-drug resistant strains of the parasite is exacerbating the situation. Febrifugine (d-1), which was isolated from Dichroa febrifuga and Hydrangea umbellata along with isofebrifugine (d-2), 1a–c is a well-known candidate antimalarial agent. The plane structure 2a of d-1 and d-2 was first proposed in 1950. ...