Question

The synthesis of $3$-octyne is achieved by adding a bromoalkane into a mixture of sodium amide and an alkyne. The bromoalkane and alkyne respectively are

• A. $BrCH_2CH_2CH_2CH_2CH_3$ and $CH_3CH_2C \equiv CH$
• B. $BrCH_2CH_2CH_3$ and $CH_3 CH_2 CH_2C \equiv CH$
• C. $BrCH_2CH_2 CH_2 CH_2 CH_3$ and $CH_3 C \equiv CH$
• D. $BrCH_2CH_2 CH_2 CH_3$ and $CH_3 CH_2 C \equiv CH$

Answer 1

Answer: (D)

$BrCH_2CH_2 CH_2 CH_3$ and $CH_3 CH_2 C \equiv CH$

Answer 2

$CH_3 CH_2 C \equiv C^- + Br - CH_2 CH_2 CH_2 CH_3$
\hspace20mm \rightarrow CH_3 CH_2 - C \equiv C- CH_2 CH_2 CH_2 CH_3
\hspace70mm _{}^{3-octyne}