NEETChemistryHaloalkanes and Haloarenes
Consider the following reaction sequence: Propanoic acid [ (ii) H ₂ O ] (i) Br ₂/ Red P A alc. KOH, B Identify the major product B.
Options
- A2-hydroxypropanoic acid
- BPropanoic acid
- CPropenoic acid
- D1,2-dibromopropanoic acid
Correct answer
C. Propenoic acid
Step-by-step solution
Propanoic acid undergoes the Hell-Volhard-Zelinsky (HVZ) reaction when treated with Br ₂ and red phosphorus followed by water. This results in the bromination of the -carbon, forming 2-bromopropanoic acid (product A). When the -halo acid A is treated with alcoholic KOH and heated, it undergoes -elimination (dehydrohalogenation). The halogen atom is removed from the -carbon and a hydrogen atom is removed from the adjacent -carbon. This elimination yields an unsaturated carboxylic acid, propenoic acid (also known as