The transesterification with 10 mg of Novozym 435, 100 mM of POH and 300 mM of vinyl acetate allowed for a remarkable 100 % conversion after 1 h of reaction at 37 °C, as shown by gas chromatography. The esterification with 300 mM of acetic acid only achieved 12 % conversion in the same timeframe, and 24 % after 2 h (Figure . and S2.). In the case of the esterification with acetic acid, 1 H NMR showed a conversion of 90 % ± 5 % after 5 days, which was estimated via the integral ratio of the hydrogens from perillyl alcohol vs perillyl acetate within the mixture (Figure .). The discrepancy between the two outcomes might be rationalized by considering that the transesterification reaction with vinyl esters can induce a shift in the reaction equilibrium. This shift occurs due to the liberation of vinyl alcohol, which subsequently isomerizes into acetaldehyde, a notably volatile compound (bp = 20.2 -20.8 °C according to PubChem). In addition to its removal from the reaction medium by evaporation, acetaldehyde is unable to act as a nucleophile in the reverse transesterification reaction, thus shifting the equilibrium to the newly formed ester. However, this alone may not sufficiently explain the substantial disparity in the reaction rates observed between the two acyl donors. Indeed, the final yield noted in the case of acetic acid also approaches the maximum, implying that the water produced is likely absorbed by the molecular sieves introduced into the reaction medium. It would be beneficial to conduct calculations on water activity to better comprehend this limitation, and to confirm whether the water produced during the reaction with acetic acid can immediately engage with the newly formed ester. Indeed, studies on the lipase-catalyzed acylation of flavonoids have shown that the water content at the beginning of the reaction, which can be provided by both the substrates and the solvent, can significantly impact the desired reactivity. Yet, it remains challenging to conceive that, after only one hour of reaction time and 12 % conversion, the significance of the reverse reaction would be so pronounced on the overall reaction rate. Therefore, a secondary explanation might be rooted in the differential affinity of the enzyme for the two acyl donors and their respective positioning within its active site. Furthermore, the lower acylation rate with acetic acid could also be due to the strong acidic character of this substrate, which can lower the pH of residual water surrounding the enzyme, as observed for octanoic acid compared to ethyl octanoate. Finally, the fact that vinyl alcohol is a very good leaving group is likely another key contributor to the higher reaction rate observed for vinyl acetate considering the 2-step ping-pong mechanism of the lipase. On the other hand, it is possible to conclude that, while it is known that acetaldehyde can act as an enzyme denaturant, it appears that the concentration levels we used do not significantly impact Novozym 435. Considering these findings, we chose to proceed with vinyl esters as acyl donors instead of their corresponding acids, aiming to maximize the yield of the desired ester. Furthermore, the complete conversion achieved with vinyl acetate can serve as a benchmark for the enzyme's ability to utilize different acyl donors tested. This will be particularly beneficial for the synthesis of STL esters, as discussed in the subsequent section of this manuscript. Moreover, the use of this methodology removes the need for a complicated workup procedure, as the immobilized enzyme can be easily recovered for future recycling, and a simple filtration followed by concentration (8 mbar, 35 °C, 1 h) was enough to remove any unreacted vinyl acetate and acetaldehyde from the medium. Thus, pure perillyl acetate was obtained, as shown on the 1 H NMR spectra (Figure S6-S8.). In addition, the absence of water generation when using vinyl esters as acyl donors theoretically eliminates the need for molecular sieves, although the latter might also contribute to the removal of vinyl alcohol/acetaldehyde from the medium. Finally, this step in the study allowed us to set up efficient reaction conditions for the acylation of terpenoids containing an allyl alcohol moiety, such as perillyl alcohol, with the immobilized form of CAL-B. It should also be noted that while the use of lipases (particularly CAL-B) for the synthesis of various monoterpenoid methyl esters with vinyl acetate is well known, to the best of our knowledge this study reports the first lipase-catalyzed synthesis of perillyl acetate. The methodology shown here could represent a viable and straightforward option for obtaining perillyl acetate in quantitative yield for future industrial applications or as an interesting potential building block.