3,4-二异丙氧基-3-环丁烯-1,2-二酮

2,4-双[4-(二乙氨基)-2-羟基苯基]方酸

3-anilino-4-hydroxycyclobut-3-ene-1,2-dione

3,4-bis(prop-2-enoxy)cyclobut-3-ene-1,2-dione

3,4-didecoxycyclobut-3-ene-1,2-dione