First preparation of single-enantiomer juvenile hormone III acid and (R)-juvenile hormone III-d₃.

The (R)- and (S)-enantiomers of juvenile hormone (JH) III acid [(R)-2 and (S)-2] were prepared by the hydrolysis of (R)- and (S)-JH III [(R)-1 and (S)-1], respectively. Each enantiomer of 2 was purified by preparative reversed-phase high performance liquid chromatography in a single operation. (RS)-2 was methylated with CH₃I and K₂CO₃ in MeCN, yielding (RS)-1. (R)-JH III-d₃ [(R)-3], a single-enantiomer internal standard for quantification, was prepared from (R)-2 with CD₃I and K₂CO₃ in MeCN.