Replacement of the phenyl ring with bicyclo [2.1.1]heptane led to either increase of clogP (Fluxapyroxad, Boscalid), or did not affect it significantly (Phthalylsulphathiazole, Lopitamide) (Scheme 4). However, in all four bioactive compounds incorporation of 2-oxabicyclo[2.1.1]hexane instead of the orthosubstituted phenyl ring led to a decrease of clogP index by ca. one unit.