1-Hydroxy-cyclobut-1-ene-3,4-dione 1-Hydroxycyclobut-1-ene-3,4-dione 3-Cyclobutene-1,2-dione, 3-hydroxy- 3-Hydroxy-3-cyclobutene-1,2-dione 3-Hydroxy-3-cyclobutenedione 31876-38-7 39284-13-4 52591-22-7 71376-34-6 BRN 1925339 CCRIS 4943 Cyclobutenedione, hydroxy- Hydroxycyclobutenedione Moniliformin NSC 292896 Semisquaric acid