The title compound, C(19)H(28)O(5)Si, was obtained in the reaction of 1,3-dihydro-4-[(tert-butyl-dimethyl-sil-yl)-oxy]-6-meth-oxy-7-methyl-3-oxo-5-(prop-2-en-yl)isobenzofuran with meta-chloro-perbenzoic acid. This reaction is one of the stages of the total synthesis of mycophenolic acid, which we attempted to modify. The title compound forms crystals with only weak inter-molecular inter-actions. The strongest stacking inter-action is found between the benzene and furan rings of inversion-related mol-ecules with a distance of 3.8773 (13) Å between the ring centroids.