Conjugate addition of 4-chloro-3-methylphenylmagnesium iodide (II) to anhydroecgonine methyl ester (I) at -40 C, followed by quenching with trifluoroacetic acid at -78 C afforded a 1:1.6 mixture of 2alpha and 2beta-3-aryltropane-2-carboxylate esters (III). The target 2beta-isomer was then isolated by column chromatography.