Reduction of artemisinin (I) with NaBH4 at low temperature provided dihydroartemisinin (II), which was subsequently converted to the alpha-acetate (III) upon treatment with acetyl chloride in pyridine. The bis(trimethylsilyl) enol ether (V) - prepared by silylation of 1,4-diacetylbenzene (IV) with trimethylsilyl triflate - was then coupled to dihydroartemisinin acetate (III) in the presence of SnCl4 at -78 C to produce a diastereoisomeric mixture of adducts (VIa-c). The title alpha,alpha-dimer was then isolated as a minor component by means of preparative HPLC.