Reaction of anhydrodihydroartemisinin 1 with halogenating reagents and further rearrangement of adducts into ring-contracted aldehydes has been revisited. The stereochemistry of reactions with iodine is opposite to that with bromine, and allowed the preparation of the new aldehyde 4 with conservation of the configuration of starting artemisinin at C-9.

中文翻译：

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环缩合青蒿素衍生物：脱水二氢青蒿素对卤化试剂的立体选择性反应

脱水二氢青蒿素1与卤化试剂的反应以及加合物进一步重排成环缩醛的反应已被重新考虑。与碘反应的立体化学与与溴相反的立体化学，并允许在维持C-9起始青蒿素构型的情况下制备新的醛4。