(i), (ii) 2-hexanone undergoes haloform reaction to form bromoform and a carboxylate ion. This carboxylate ion undergoes hydrolysis to give pentanoic acid. CH3CH2
CH2H2
C
||
O
2−hexanone
−CH3
(i)NaOBr
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(iii), (iv) Pentanoic acid, react with bromine in presence of red-phosphorus to give alpha-bromocarboxylic acid. This reaction is Hell-Volhard-Zelinsky reaction.