CONFIGURATIONAL EFFECTS IN O-17 NMR CHEMICAL-SHIFTS OF HYDROXYL-SUBSTITUTED BICYCLO[2.2.1]HEPTENES AND BICYCLO[2.2.1]HEPTANES, THEIR METHYLATED DERIVATIVES AND SOME RELATED-COMPOUNDS

Well resolved natural abundance O-17 NMR spectra of 27 mono-, di-, tri - and tetrahydroxybicyclo[2.2.1]heptenes and -heptanes (norbornenes or norbornanes), their methylated derivatives and some related compounds were measured for 0.5 M or saturated solutions in acetonitrile at 65- degrees-C. In addition, the O-17 NMR chemical shifts of 14 aliphatic a nd alicyclic alcohols were also determined for reference purposes. The O-17 NMR chemical shifts of all compounds were assigned. Both methyl- and hydroxyl-induced deshielding beta-effects were consistent with th ose reported in the literature. Similarly, observed shielding gamma-ef fects were in agreement with the earlier observations and characterist ic especially for mutual gamma-gauche and -eclipsed orientations of su bstituents. In addition, clear shielding delta-effects (up to 10 ppm) were observed in tri- or tetrahydroxynorbornanes. These delta-effects can be related to the attractive van der Waals interactions observed e arlier in C-13 NMR chemical shifts.