dimethyl (1R,4S,4aS,8aR)-5,8-dioxo-1,4,5,8-tetrahydro-1,4-etheno-4a,8a-methanonaphthalene-2,3-dicarboxylate

2,3,4,5-Tetramethyl-anti-tricyclo[4.4.0.02,5]deca-3,7,9-trien-1,6-dicarbonsaeure-dimethylester

马来酸二甲酯

dimethyl 3-cyano-3-methoxytetracyclo[3.2.0.02,7.04,6]heptane-1,5-dicarboxylate

dimethyl 3-oxotetracyclo(3.2.0.02,7.04,6)heptane-1,5-dicarboxylate