Reduction of artemisinin (I) by means of NaBH4 in THF/MeOH followed by treatment with BH3稨2O in MeOH yields (II). Finally, beta-artemether (II) is condensed with TMS-enol ether (IV) [obtained by protection of diacetylbenzene (III) by means of TMSOTf and Et3N in THF] in the presence of TiCl4 in CH2Cl2.