Both antipodes of α-methyl-α-methoxyarylacetic acid derivatives were prepared from a common chiralpool precursor l-(+)-tartaric acid. The key step involves the addition of Grignard reagents to 1,4-diketones derived from tartaric acid. The utility of this strategy was applied in the formal enantioselective synthesis of pine beetle pheromone (-)-frontalin. © 2006 Elsevier Ltd. All rights reserved.