SUBSTITUENT-INDUCED CHEMICAL-SHIFTS OF AROMATIC CARBON CENTERS IN A SERIES OF NON-ACETYLATED AND PERACETYLATED PARASUBSTITUTED ARYL 2-N-ACETAMIDO-2-DEOXY-BETA-D-GLUCOPYRANOSIDES

The additive behaviour generally observed for the substituent-induced chemical shifts (SCS) for disubstituted benzenes was examined for a se ries of aryl 2-N-acetamido-2-deoxy-beta-D-glucopyranosides having a wi de range of para substituents with varying possible electronic contrib utions. The SCS values associated with nonacetylated and peracetylated glucoside rings in para-substituted aryl 2-N-acetamido-2-deoxy-beta-D -glucopyranosides were calculated. The additive nature of SCS analysis for para-substituted systems was shown to hold for the meta and para positions but the very small change in chemical shifts for the ortho p ositions precluded attempts at analysis of these data. The observation of a good correlation for the ipso carbons for the acetylated compoun ds compared with a poor correlation for the same site in the non-acety lated compounds is not well understood.