Preparation of (±)-[1,2- 13 C 2 ]Abscisic Acid for Use as a Stable and Pure Internal Standard †

Abstract

[1,2-¹³C₂]ABA, which is designed as a stable and pure internal standard for GC/MS analysis, is synthesized through the Witting reaction of 1-hydroxy-4-keto-α-ionone with carbomethoxymethylenetriphenylphosphorane prepared from [1,2-¹³C₂]bromoacetic acid followed by saponification of the product methyl [1,2-¹³C₂]ABA.