JEE MainChemistryGeneral Organic Chemistry
Which of the following organic compounds is incorrectly named according to IUPAC rules?
Options
- ACH₃-C(O)-CH₂-CH₂-COOH : 4-Oxopentanoic acid
- BCH₃-CH(OH)-CH₂-C(O)-CH₃ : 4-Hydroxypentan-2-one
- CHC C-CH₂-CH=CH₂ : Pent-4-en-1-yne
- DCH₂=CH-CH₂-CN : But-3-enenitrile
Correct answer
C. HC C-CH₂-CH=CH₂ : Pent-4-en-1-yne
Step-by-step solution
Let us evaluate the IUPAC name for each option: For CH₃-C(O)-CH₂-CH₂-COOH , the principal functional group is the carboxylic acid. Numbering starts from the carboxyl carbon, placing the ketone (oxo group) at C4. The name 4-Oxopentanoic acid is correct. For CH₃-CH(OH)-CH₂-C(O)-CH₃ , the ketone has higher priority than the alcohol. Numbering from right to left gives the ketone the lower locant (C2) and the hydroxyl group is at C4. The name 4-Hydroxypentan-2-one is correct. For CH₂=CH-CH₂-CN , the nitrile carbon is in