3999-67-5
tetramethyl cyclobutane-1,2,3,4-tetracarboxylate
→
~93%
720-21-8
cyclobutane-1,2,3,4-tetracarboxylic acid
108-31-6
马来酸酐
+
67-56-1
甲醇
2756-87-8
富马酸单甲酯