Q40 / 200 · WBJEE 2013 · Chemistry
The best method for the preparation of 2, 2-dimethylbutane is via the reaction of
- A$\mathrm{Me}_{3} \mathrm{CBr}$ and $\mathrm{MeCH}_{2}$ Br in Na/ether
- Correct answerB$\left(\mathrm{Me}_{3} \mathrm{C}\right)_{2} \mathrm{CuLi}$ and $\mathrm{MeCH}_{2} \mathrm{Br}$
- C$\left(\mathrm{MeCH}_{2}\right)_{2} \mathrm{CuLi}$ and $\mathrm{Me}_{3} \mathrm{CBr}$
- D$\mathrm{Me}_{3} \mathrm{CMgl}$ and $\mathrm{MeCH}_{2}l$
Solution
2,2 - dimethyl butane is prepared from Corey House alkane synthesis. $\left(\mathrm{Me}_{3} \mathrm{C}\right)_{2} \mathrm{Cul}_{2} \mathrm{Li}+\mathrm{MeCH}_{2} \mathrm{Br} \stackrel{\mathrm{S}_{\mathrm{N}}{2}}{\longrightarrow}$
$$
\mathrm{Me}_{3} \mathrm{C}-\mathrm{CH}_{2} \mathrm{CH}_{3}+\mathrm{Me}_{3} \mathrm{C}CuLi
$$
Hence, the correct answer is option: 'B'.