Q. 2,3-Dimethyl-2-butene can be prepared by heating which of the following compounds with a strong acid ?
A) $(CH_3)_2C=CH-CH_2-CH_3$
B) $(CH_3)_2CH-CH_2-CH=CH_2$
C) $(CH_3)_2CH-CH(CH_3)-CH=CH_2$
D) $(CH_3)_3C-CH=CH_2$
Explanation
[Solution] Protonation of $(CH_3)_3C-CH=CH_2$ gives a 2° carbocation; a methyl shift gives the 3° carbocation $(CH_3)_2C^+-CH(CH_3)_2$, and loss of $H^+$ gives $(CH_3)_2C=C(CH_3)_2$. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.