Question

Show how you might synthesize the following compounds, using acetylene and any suitable alkyl halides as your starting materials. If the compound given cannot be synthesized by this method, explain why.

(a) hex-1-yne
(d) 4-methylhex-2-yne

Answer 1

(a) To synthesize hex-1-yne using acetylene and suitable alkyl halides, you can start with 1-bromohexane. Treat 1-bromohexane with a strong base, such as sodium amide (NaNH2), to remove the bromine atom and form the corresponding alkynyl anion. Then, react the alkynyl anion with acetylene to form hex-1-yne.

(d) To synthesize 4-methylhex-2-yne using acetylene and suitable alkyl halides, you can start with 4-bromo-2-methylhexane. Similar to the previous synthesis, treat 4-bromo-2-methylhexane with a strong base to generate the alkynyl anion. Then, react the alkynyl anion with acetylene to form 4-methylhex-2-yne.

Both compounds can be synthesized using acetylene and suitable alkyl halides through the elimination reaction to form the carbon-carbon triple bond.