Q. RBr —(i) Mg, dry ether; (ii) H₂O→ 2-Methylbutane The maximum number of RBr producing 2-methylbutane by above sequence of reactions is ________ - (Consider the structural isomers only)
A) 5
B) 4
C) 3
D) 1
Explanation
[Solution by Dr. Abubacker] The Grignard reagent formed from RBr is hydrolysed to R–H, so R must have the 2-methylbutane carbon skeleton. Replacing H by Br at each type of carbon gives four distinct bromides: 1-bromo-2-methylbutane, 2-bromo-2-methylbutane, 2-bromo-3-methylbutane and 1-bromo-3-methylbutane. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.