We started our mechanistic explorations from the biologically relevant form of ribose, i.e., the α-D-furanose form, and considered various possible pathways to prepare this species for eventual reaction with the uracil nucleobase. As such, we computed a variety of plausible concerted and stepwise mechanisms resulting in the installation of a phosphoric acid moiety on the ribose. Our calculations unequivocally indicate that for regular ribose, neither concerted, S N 2-like, nor stepwise phosphorylation pathways, proceeding via a pentavalent phosphorous intermediate, are feasible -typical reaction barriers amount to 40-60 kcal/mol, and electric fields aligned with the dipole moment of the reacting system only affect these barriers by a couple of kcal/mol at best (see Figure ). When applying the field along various directions in three dimensions it becomes apparent that the one coinciding with the dipole moment is associated with the strongest catalysis (Z-axis in Figure ). It is however not the only field orientation leading to non-negligble barrier modulation. The orientation corresponding to the bond-breaking orientation also induces changes comparable to when the field is aligned with the dipole moment.