Question

$C{H}_3-C{H}_2-\underset{C{H}_2}{\underset{||}{C}-}COOH$
The correct IUPAC name of the above compound is:

• A. $2$-methyl butanoic acid
• B. $2$-Ethylprop-$2$-enoic acid
• C. $2$-carboxy-$1$-butene
• D. none of these

Answer 1

Answer: (B)

$2$-Ethylprop-$2$-enoic acid

According to IUPAC rules, the priority order is

1. Functional groups $-COOH$
2. Double bond at 2nd position
3. No. of carbons in a chain $3$

So the name of the compound is 2-ethylprop-2-enoic acid.