JEE Advanced 2015 · Paper 2 · Chemistry Q29

← JEE Advanced 2015 · Paper 2

ChemistryMultiple correct+4 / -2Question 29 of 60

In the following reactions, the product S is

6-Methylindene (a methyl-substituted indene) treated with i. O₃, ii. Zn, H₂O to give R, then NH₃ to give S.

7-Methylisoquinoline: isoquinoline with a methyl group at C7.

7-Methylquinoline: quinoline with a methyl group at C7.

6-Methylisoquinoline: isoquinoline with a methyl group at C6.

6-Methylquinoline: quinoline with a methyl group at C6.

Answer and worked solution

Official answer: A

Ozonolysis (R). Ozonolysis of the indene C=C opens the five-membered ring. It gives a dicarbonyl with CHO on one ring carbon and CH₂CHO on the adjacent one.

Ring closure (S). NH₃ condenses with both carbonyls (imine formation and cyclisation). Aromatisation gives an isoquinoline. The ring methyl ends up at C7.

(A)

Topics:Alkenes Nucleophilic addition

← Previous question Next question →

JEE Advanced 2015 · Paper 2, Chemistry question 29