1) 3-Ethyl-2-hydroxy-2-cyclopenten-1-one 3-乙基-2-羟基-2-环戊烯-1-酮2) 2-Cyclopenten-1-one, 3-ethyl-2-hydroxy- (7CI, 8CI, 9CI) 3-乙基-2-羟基-2-环戊烯-1-酮(7CI,8CI,9CI)3) 3-methyl-2-hydroxy-cyclopent-2-en-1-one 3-甲基-2-羟基环戊-2-烯-1-酮...