Abstract: α(p-cl-phcnyl) isoamyl acid is an important intermediate of synthetic pyr-ethroid. There are a chiral center and two prochiral methyl groups iu its structure. In order to understand the co-relation between structure and bioactivily, one must give a detailed observation on its stuclural specifications. Our work included the separation of ¹H and ¹³C signals of the enanfiomers with chiral LSR Eu (hfbc)₃ and LSR Eu (fod)₃, assignments of the diastereotopic methyl groups and the corelation between the magnitude of the anisochrony produced by the methyl groups and neighbor substitutes. Experimenls coincide with the calculation results from a simplified model.

Key words: Chirality, Prochirality, Chiral LSR, Paramagnetic shift