Simplified analogues of qinghaosu (artemisinin)

Three new simplified analogues of qinghaosu have been designed and synthesized through simple routes without recourse to the commonly employed photosensitized oxidation. The peroxy bonds in the target molecules were taken from UHP with the first peroxy–carbon bond formed through a hemiketal exchange reaction and the second by either an intramolecular Michael addition or a Hg(II)-mediated ring-closure reaction. All three peroxides possess a seven-membered peroxy ring fused to an all-carbon six-membered ring, a structural motif required for generating the carbon-centered substituted ethyl radicals.