Decomposition reactions of arteether, a semisynthetic derivative of qinghaosu (artemisinin)

Arteether, an antimalarial derivative of qinghaosu, is extensively decomposed in acid aqueous media. The decomposition products include an α,β-unsaturated decalone and α,β-unsaturated aldehydes. Formation of the latter involves the unusual partial hydrolysis of acetal ring of arteether to an ether function. The endoperoxide group of arteether is also readily attacked by sodium dithionite in an alkaline medium to give a product in which both peroxidic oxygens have been eliminated while the acetal ring is unaffected. In a neutral medium, however, the product of reduction is a diol.