Several methods were described earlier for the synthesis of 5,6,7,8,9,10-hexahydro-5,9-methanobicyclobenzocyclooctene (5). A novel simple method is described in this paper by the persulfate (II)/silver (I) ion catalyzed decarboxylation refluxing in water-acetonitrile mixture from corresponding 4 carboxylic acid, which was prepared earlier in four steps starting from tetrahydrophthalic anhydride (1).