Chapter 11: Q51. (page 452)

Question: Synthesize each compound from acetylene. You may see any other organic or inorganic reagents.
a.
b.
c.
d.
e.

Short Answer

Expert verified

Answer

The given compounds can be synthesized from acetylene by the following chemical equations:

Step by step solution

Step-by-Step SolutionStep 1: Reactivity of acetylene

Acetylene is the simplest alkyne. Alkynes undergo addition reactions that are similar to alkenes due to the presence of a weak bond.

Due to the sp hybridization of the alkynes, the carbon and hydrogen bonds are acidic in nature. The alkynes also undergo hydrohalogenation reactions for the addition of halogens from the alkyl halides.

The synthesis of the given compounds a and b by using acetylene

The given compound can be synthesized using the acetylide anion. The alkyl halide used in this reaction is 1-chloro-3-methyl propane. The following is the reaction for the same:

The given compound can be synthesized using acetylide ion and chloropropane as the alkyl halide in the first part of the reaction. The reaction takes place in the following steps:

In the second part of the reaction, the alkyne ${CH}_{3} {CH}_{2} {CH}_{2} C \equiv CH$ is then treated ${CH}_{3} {CHCH}_{2} - Cl$ with NaH and to obtain the requi

The synthesis of the given compounds c, d, and e by using acetylene

c. The given compound can be prepared using the pent-1-yne and chloropropane as the starting material. The pent-1-yne is prepared using acetylene as follows:

Now, the pent-1-yne obtained from the above equation reacts with chloropropane in the following equation:

d. The given compound is prepared by the alkyne obtained from equation (b), and then treating it with and , as shown in the following equation:

e. The given compound is prepared from the alkyne obtained from equation (b) in the following equation:

In the next step, the alkyne obtained in the above equation is treated with $H_{2} O, {HgSO}_{4} and H_{2} {SO}_{4}$ and to obtain the desired product: