High-field 2Hmr spectrometry of deuteriated 1,3,3-trimethylbicyclo[2.2.1]heptan-2-ones. Determination of geminal deuterium isotope effects on deuterium chemical shift

By a high-field 2 Hmr study of deuteriated 1,3,3-trimethylbicyclo[2.2.1]heptan-2-ones (fenchones), we have established that the geminal deuterium isotope effects on the exo-6-, endo-6-, and methyl deuterons are 1.46 ± 0.06 Hz (0.019 ppm), 1.61 ± 0.06 Hz (0.021 ppm), and 1.46 ± 0.06 Hz (0.019 ppm), respectively. From this study it is clear that high-field 2 Hmr has the potential of providing directly all the information on the degree of …