With the chiral acceptors in hand, the glycosylations in Figure were carried out, with both 1-α or 1-β as the donor, and the reactions were followed by in situ IRspectroscopy. The kinetic trace from a distinct peak at 1670 cm -1 from the donor was used to fit different integrated rate laws, and it was found that the reactions seem to follow the rate law for a bimolecular reaction with different reactants of different concentrations (See SI Section 3.1 for details). The fitted kinetic traces are shown in the plot in Figure , and the calculated rate constants can be found in Table . No major differences in the rates are observed, although the glycosylations with 5-(R) are slightly slower than the glycosylations with 5-(S). The rate of the glycosylations with 5-(R) seems to be independent of the donor configuration, whereas, for the glycosylations with 5-(S), 1-α seems to be a better match for the acceptor. Despite no major differences in the rate between the glycosylations with 1-α and the glycosylations with 1-β, a great difference in anomeric selectivity is observed. For the glycosylations with 1-α only the β-product is observed but for the glycosylations with 1-β a mixture of anomers is observed, which is in agreement with previous observations. 14 Table : Rate constants determined from second order integrated rate law plot in Figure and α : β ratio of N -glucoside product with standard deviations.