Question Detail

CHM 102 Practice Questions Objective Question

Question

Starting with 2-butene, which of the following is the best method for preparing 2-butyne?
Options
A HBr; H2/Ni; Zn/H+
B HBr; Zn/H+; H2/Ni
C Br2/CCl4; Zn/H+; H2/Ni
D Br2/CCl4; 2NaNH2
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

2-Butene can be converted to 2-butyne by first adding Br2 to give 2,3-dibromobutane, followed by double dehydrohalogenation with excess NaNH2 (strong base) to eliminate two equivalents of HBr, forming the alkyne.

Hint

How can an alkene be converted to an alkyne?

Question Info