JEE MainChemistryCarboxylic Acid Derivatives
Consider the following reaction sequence: CH₃CH₂CH₂C N H₃O^+/ X [ (ii) H₂O] (i) Br₂/ Red P Y alc. KOH, Z (Major product) The IUPAC name of the major product 'Z' is:
Options
- A2 -Hydroxybutanoic acid
- BBut- 2 -enoic acid
- CBut- 3 -enoic acid
- D2 -Bromobutanoic acid
Correct answer
B. But- 2 -enoic acid
Step-by-step solution
Step 1: Complete hydrolysis of butanenitrile under acidic conditions yields butanoic acid. CH₃CH₂CH₂C N H₃O^+/ CH₃CH₂CH₂COOH (X) Step 2: Butanoic acid undergoes the Hell-Volhard-Zelinsky (HVZ) reaction with bromine and red phosphorus, which selectively substitutes an -hydrogen with bromine to form 2 -bromobutanoic acid. CH₃CH₂CH₂COOH [ (ii) H₂O] (i) Br₂/ Red P CH₃CH₂CH(Br)COOH (Y) Step 3: Treatment of an -halo acid with alcoholic KOH and heat causes dehydrohalogenation (an E2 elimination). The -bromine and a -hydro