Which is the most efficient synthesis of (Z)-3-hexene from C2H2?

Answer 1

One of the most efficient syntheses of (Z)-3-hexene from C2H2 involves the following steps:

1. React C2H2 (acetylene) with HBr (hydrogen bromide) to form 1-bromoethylene.
C2H2 + HBr -> CH2=CHBr

2. Perform a nucleophilic substitution reaction on 1-bromoethylene using NaCN (sodium cyanide) to obtain 1-cyanoethylene.
CH2=CHBr + NaCN -> CH2=CHCN

3. Convert 1-cyanoethylene to 3-hexenenitrile through hydrolysis using HCl and water.
CH2=CHCN + 2H2O + HCl -> CH3(CH2)3CN

4. Finally, reduce 3-hexenenitrile using lithium aluminum hydride (LiAlH4) in dry diethyl ether to obtain (Z)-3-hexene.
CH3(CH2)3CN + 4[H] -> CH3(CH2)3CH=CH2

It is important to note that this is just one of the several possible synthetic routes to achieve the desired product, and the choice can be influenced by factors such as availability of reagents, safety considerations, and overall efficiency in terms of yields and purification steps.