H-1 AND P-31 NMR-STUDY OF THE SUBSTITUENT -EFFECTS OF ALPHA-OXYALKYLPHOSPHONATES

H-1 and P-31 NMR spectroscopies were used to study 21 compounds of alp ha-(2-benzoxazolyl)oxyacetoxyalkyl-phosphonate. It is indicated that t he non-equivalence between the two ester OR' groups is affected by the alpha-substituentes. The larger the substituent is, the greater the d ifference of H-1 chemical shifts between the two ester OCH3 groups is. The alpha and ester substituents also affected alpha-magnetic nuclei, that is alpha-H and alpha-P-31. The regular dependences of their chem ical shifts, as well as their scalar coupling interaction, on the subs tituents were discussed in detail.