Question

Which of the following compounds cannot be prepared singly by the Wurtz reaction?

A. C₂H₆
B. (CH₃)₂CHCH₃
C. CH₃CH₂CH₂CH₃
D. All of the above can be prepared

Answer 1

Compound B. (CH3)2CHCH3 (isobutane) cannot be prepared singly via the Wurtz reaction due to potential side reactions creating a mix of products. The Wurtz reaction is generally unsuitable for producing highly branched or cyclic compounds.

Step-by-step explanation:

The Wurtz reaction is a coupling reaction in organic chemistry, used to create a new carbon-carbon bond between two alkyl halides, using sodium. However, the reaction has restrictions on the types of compounds it can synthesize effectively. It is not suitable for the preparation of highly branched or cyclic compounds, due to the possibility of side reactions leading to a mixture of products.

The compounds listed in the student's question are A. C2H6 (ethane), B. (CH3)2CHCH3 (isobutane), and C. CH3CH2CH2CH3 (butane). Isobutane, being a highly branched alkane, cannot be prepared cleanly via the Wurtz reaction, because the reaction would likely result in a mixture of products rather than the desired single compound due to steric hindrance. Therefore, the correct option in the final answer is B. (CH3)2CHCH3, as it cannot be prepared singly by the Wurtz reaction.