Question: Draw the organic products formed in each reaction

a.

b.

Acetylides are compounds having a terminal alkyne group in their structure. When these compounds are treated with a strong base, acetylide anions are formed.

The general reaction is shown below

Formation of acetylide anion

After the acetylide anions are formed, they act as strong nucleophile and can participate in nucleophilic substitution when reacted with alkyl halides.A general reaction is shown below:

Type reaction of acetylide with an alkyl halide

a.

The base attacks at the terminal alkyne hydrogen, and the nucleophile is formed. The nucleophile then attacks at the alkyl halide given.

The mechanism is given below:

Acetylide anion reaction with the given alkyl halide

b.

The mechanism of the reaction is mentioned below:

Acetylide anion reaction with the given alkyl halides

With the $3°$ alkyl halide, elimination takes place rather than substitution since the carbocation is too crowded for substitution to occur.