Question

A compound named 5-(-1-Cyanoethyl)-2-methyl hexanoic acid has something wrong according to IUPAC. What is correct IUPAC name?

• A. 5-Ethylcyanide-2-methylhexanoic acid
• B. 6-Cyano-2,5-dimethylheptanoic acid
• C. 6-Cyano-5-methyl-2-heptanoic acid
• D. 6-Carboxy-2,3-dimethylheptanenitrile

Answer 1

The correct option is B 6-Cyano-2,5-dimethylheptanoic acid

As CN is behaving as substituent here because priority order of carboxylic acid is on the top.

Carboxylic acids ( -COOH )
Suffix: oic acid/carboxylic acid

Nitriles ( -C≡N )
Prefix : cyano
Alkyl(-R) group do not have any priority order and considered substituents while numbering

The compound with correct numbering of parent chain is
Hence, correct IUPAC name is
6-Cyano-2,5-dimethylheptanoic acid