A new method for the preparation of arteether and its C-9 epimer

Abstract

Arteether [4] was obtained by treating anhydrodihydroartemisinin [3] with absolute EtOH in the presence of p-toluenesulfonic acid as a catalyst. 9-epi-Arteether [6] was obtained as the minor product. The use of CH2Cl2 as a solvent yielded the latter as the major product. Its structure and absolute stereochemistry were unambiguously established from its spectral data and by X-ray crystallographic analysis. This procedure permitted the preparation of C-9 deuterated arteether [5], which may be needed for metabolic studies. © 1992, American Chemical Society. All rights reserved.