Conversion of antimalarial drug artemisinin to a new series of tricyclic 1,2,4-trioxanes1.

A highly efficient route for the conversion of the antimalarial drug artemisinin to a novel hydroxy-functionalized tricyclic 1,2,4-trioxane 6 is reported. Neither the trioxane 6 nor its derivatives 14-16, all of which lack the hydrolytically unstable acetal-lactone linkage, show antimalarial activity comparable with that of artemisinin.