... Issue. European Journal of Organic Chemistry. ... The residue was taken up in CH 2 Cl 2 (5 mL) and extracted with aqueous EDTA solution (0.5 M, 2 × 10 mL). The organic layer was dried with Na 2 SO 4 and evaporated to give pure methyl ester. ... Eur. J. 2001 , 7 , 5135 –5142 . ...