..............................
The IUPAC names for these two compounds are
| ................................cis-butendioic acid | ............................................trans-butendioic acid |
| .......................................m.p. 130oC | ......................................................m.p. 287oC |
Further comparisons of these two compounds:
When maleic (cis-butendioic) acid is heated, it
loses water readily to form maleic anhydride.
When fumaric (trans-butendioic) acid is
heated to 300oC, it rearranges to form maleic (cis-butendioic)
acid, which then forms maleic anhydride.
What happens when maleic acid and fumaric acid are hydrogenated?
When hydrogenated, each of the two isomers forms the same product, succinic acid (butanedioic acid).
Why is there only one form of succinic (butanedioic) acid?
Succinic (butanedioic) acid is a saturated -dioic acid. It contains no double (-C=C-) bonds.
