Acetylation of (S)-perillyl alcohol 100 mM of perillyl alcohol and 300 mM of acetic acid or vinyl acetate were dissolved in the solvent mixture in the presence of 3 Å molecular sieves. 1 mL of the resulting solution was introduced into a 2 mL vial containing 10 mg of Novozym 435 and 3 spheres of 5 Å molecular sieves. Controls were performed in the same conditions in the absence of the enzyme. 25 µL samples were taken at different time intervals and dissolved in 225 µL of acetonitrile (LCMS grade). They were then filtered on 0.2 µm PFTE filter and introduced into GC vials for analysis.