Table . Comparisons to the experimental results -the ketone selective and epoxide selective reactions. 'Calculated percentage (TST)' is derived based on the TST assumption. The selectivity of the reaction entirely depends on the kinetics of TS1 and TS2. 'Calculated percentage (with VRAI)' incorporates the VRAI-selectivity calculation outcomes. We assume that the stereochemistry is controlled by kinetics via TS1 and the chemoselectivity, ie processes beyond TS1, are controlled by reaction dynamics. The selectivity of the aldehyde selective reaction was found to be controlled by reaction dynamics entirely. The most stable TS1(RR), with a stereochemistry of RR at C4 and C5 position, do not lead to the major product, R aldehyde. The earlier study of Wei et al., the selectivity is rationalized based on TST. Starting from the most stable TS1 from their publication, which has a RS stereochemistry at C4 and C5, we reinvestigated the system, using a functional with a dispersion correction and thorough conformational exploration. This led to a different conclusion from TST which was now incompatible with the experimental result (SI Table .1). We investigated, therefore, whether the stereochemistry of the reaction may also be controlled by reaction dynamics. The drop in energy from TS0, the TS for the COBI catalyst and aldehyde complexation, to INT1 is more than 10 kcal mol -1 . TS0 is more than 2.5 kcal mol -1 higher compared to the most stable TS1 (Figure .A). We conducted an additional VRAI-selectivity calculation with TS0 as the TS I and INT1 as the intermediate. The products are stereoisomers of INT2, INT2(RR) and INT2(RS). As the lowest energy TS2 to the epoxide is higher in energy than the corresponding TS1, this pathway is considered to be unfavourable kinetically. The final product percentages with VRAIselectivity results were calculated based on three sets of VRAIselectivity calculations. The Sankey diagram in Figure .C provides the details to the calculation. The calculated percentages incorporating VRAI-selectivity calculation results show a better match with the experimental result than the calculated percentages based on TST (Table ). This implies that both the stereochemistry and chemoselectivity in the aldehyde selective reaction may be influenced by reaction dynamics.