JEE Advanced levelSingle correct optionDifficulty 3 of 3co130
Compound A, CX5HX10O, gives a yellow precipitate with IX2/NaOH and does not reduce Tollens reagent. Clemmensen reduction of A gives straight-chain pentane. A is treated with excess NaOI and then acidified to give acid B. B is
Apropanoic acid
Bpentanoic acid
C2-methylpropanoic acid
Dbutanoic acid
Answer: D
Iodoform positive and Tollens negative means a methyl ketone. Clemmensen reduction to unbranched pentane fixes A as pentan-2-one, CHX3COCHX2CHX2CHX3. The haloform reaction gives CHX3CHX2CHX2COOX−, so B is butanoic acid.