Question

The correct IUPAC name of

• A. Methane-tri-carboxylic acid
• B. 2-Carboxy propane-1, 3-dioic acid
• C. 1, 2, 3-Propanetrioic acid
• D. 1, 2, 3-butanetrioic acid

Answer 1

The correct option is A

Methane-tri-carboxylic acid

clearly there is no way we can choose the longest chain without excluding one $-\stackrel{O}{\stackrel{||}{C}}-OH$ or -COOH
group.In this can we do not count any of the -COOH carbons as part of the primary chain.Instead ,all
three $-\stackrel{O}{\stackrel{||}{C}}-OH$ groups are treated as substituents

-COOH is carboxylic acid group.
There are three of them ,each replacing a Hydrogen atom of a methane molecule.

Hence the IUPAC name is
(a) methane -tri-carboxylic acid

Note:methane - tri-carboxylic is one word.