What type of isomer is Maleic Acid?

1 Answer
Mar 22, 2016

A cis geometric isomer, i.e. a type of diastereomer found in alkenes.

https://upload.wikimedia.org/

Maleic acid is otherwise known as cis-butenedioic acid, which has a double bond that is flanked by two carboxylic acid groups. Maleic acid, a geometric isomer, is thus a diastereomer and therefore a stereoisomer.

An important distinction to make here is that maleic acid is the cis isomer, whereas fumaric acid is the trans isomer!

http://staff.um.edu.mt/

If someone asks you to draw maleic acid, and you draw trans-butenedioic acid, you haven't drawn maleic acid! You've drawn its trans, geometric isomer, fumaric acid.