Site specific C-13 labeling of anhydrous glucose is used to study the time scale and geometry of reorientational motion of the exocyclic CH2OH group in relation to the main glucose ring. By comparison of 2D echo decay NMR experiments with Monte Carlo simulations a bimodal distribution of jump angles, a 75% fraction of 1-2 degrees jumps and a 25% of 7-8 degrees jumps, is found to describe the geometry of the reorientational processes of the main ring. For the CH2OH group the average jump angle of the larger jump process is somewhat larger. The jump rates for both the CH2OH group and the ring are similar. The apparent activation energy determined for the rotational motion of the CH2OH group and the ring is 480 +/- 40 kJ/mol, which is very similar to an earlier determination using viscometry. It is concluded that the glucose ring and the exocyclic CH2OH-group mobility are strongly correlated and that the rotational freedom of the CH2OH group should not be used to explain the faster p-relaxation process also found for glucose.