Stereoselective synthesis of asarone (I) by the reaction of 2,4,5-trimethoxybenzaldehyde and the appropriate Grignard or Wittig reagent under different conditions was described. In the approach with Grignard reaction, the major product was a-(E)-asarone, while the major product was either a-(E)- or b-(Z)-asarone in the Wittig approach depending on the reaction conditions.

Key words: METHOXY GROUP, WITTIG REACTION, ORGANIC SYNTHESIS, GRIGNARD REACTION, BENZALDEHYDE, STEREOSELECTIVITY, ASARONE