Which of the following alkanes may be synthesized from a single alkylhalide by a process involving coupling reaction.

Explanation

Coupling reactions involve the formation of new carbon-carbon bonds, typically through reactions that utilize organometallic reagents such as those used in the Wurtz reaction or Corey-House synthesis.

In these reactions, two alkyl halides can couple in the presence of sodium metal or a copper reagent to form a higher alkane.

Analyzing the Options

1. 2-Methyl butane: This compound can be synthesized from 1-bromobutane through a coupling reaction with methyl iodide.
2. 2-Methyl propane: This compound (also known as neopentane) is not easily synthesized from a single alkyl halide through coupling because it requires specific branching that cannot be achieved from a single precursor.
3. 2,3-Dimethyl butane: This compound can be synthesized from 1-bromobutane and 1-bromo-2-methylpropane through coupling reactions.
4. Propane: Propane could theoretically be formed from 1-bromopropane, but it does not require a coupling reaction since it can be formed directly by simpler methods.

Conclusion

The most suitable option that can be synthesized from a single alkyl halide via a coupling reaction is: a. 2-Methyl butane

This is because it can be formed from a single alkyl halide (like 1-bromobutane) reacting with another alkyl group (like methyl) through a coupling mechanism. Thus, the answer is a. 2-Methyl butane.