2-氮杂螺[4.4]壬烷-1,3-二酮

2-oxaspiro[4.4]nonan-1-one

1,1-环戊基二羧酸

4-(1,3-dioxo-2-azaspiro[4.4]nonan-2-yl)benzoic acid

2-anilino-2-azaspiro[4.4]nonane-1,3-dione