“…Moreover, these species are located in different cavities of the LDH structure (i.e., gallery, narrow and larger mesopores) and in different structural orientations. Obviuosly, some of these molecules are not able to act as catalytic active sites, if their environment is not large enough to allow the diffusion of the reactant molecules (i.e., trans-methylcinnamate) and the formation of the spirotransition state, in which the plane of the oxirane is perpendicular to the plane of the C C -system permeating the oxygen transfer [18,39] (Scheme 1). The kinetic diameter of trans-methylcinammate (6.7 Å) and the corresponding phenyl-glycinate product (7.1 Å) has been estimated from the molecular weight correlation, using the equation: For aromatic hydrocarbons (M w = molecular weight in g mol −1 ) [40].…”