The presence of this entropic intermediate is further confirmed by downhill dynamics initiated from the TS (Fig. and Table ). For endo reaction, the trajectories reveal a significantly more asynchronous reaction in explicit solvent compared to implicit solvent, in agreement with the ACE-MD/US data. The asynchronicity in the downhill dynamic is evident in the increased average time gap between the formation of the two C-C bonds, from 19.9 fs in an implicit water solvent to 84.3 fs in an explicit solvent. It is worth noting that although the average time gaps observed in the water exceeded 60 fs (the time gap A comparison of the average time gap for the reactions in explicit water and methanol reveals that the latter exhibits a more concerted mechanism, with a time gap of 24.8 fs.