Spiro[2,bicyclo [4.2.0]octane]-7'-one with fused and spirocyclic oxygen-containing rigid skeleton structure is obtained via Wolff rearrangement and cycloaddition with good yields. Then Spiro[2,2-dimethyl-benzofuran,hexahydro-isobenzofuran]-7'-one is synthesized by further Baeyer-Villiger oxidation. These two kinds of products have a special fused and spirocyclic oxygen-containing rigid skeleton structure and are reported by our group.