JEE Advanced 2018 · Paper 1 · Chemistry Q5

ChemistryMultiple correct+4 / -2Question 23 of 54

The reaction(s) leading to the formation of 1,3,5-trimethylbenzene is (are)

Answer and worked solution

Official answer: A, B, D

(A) Acetone with conc. $\ce{H2SO4}$ undergoes three aldol-type condensations with dehydration, giving mesitylene. Yes.
(B) Propyne passed through a red-hot iron tube cyclotrimerises to 1,3,5-trimethylbenzene. Yes.
(C) The haloform reaction turns each $\ce{COCH3}$ into $\ce{COOH}$ . Soda-lime then decarboxylates all three, giving benzene. No.
(D) Clemmensen reduction turns each $\ce{CHO}$ into $\ce{CH3}$ , giving mesitylene. Yes.

(A), (B), (D)

JEE Advanced 2018 · Paper 1, Chemistry question 5