Question

How would you prepare cis-2-butene starting from propyne, an alkyl halide, and any other reagents needed? This problem can’t be worked in a single step. You’ll have to carry out more than one reaction.

Short answer

Reagents are the compounds which are used for conversion or addition or elimination of different functional groups from the reactant species.

Step-by-step solution

Definition reagents

Reagents are the compounds which are used for conversion or addition or elimination of different functional groups from the reactant species.

Formation of cis-2-butene

Given reactant is propyne

The formation of product will takes place by the use of three reagents:

1 ${\mathrm{NaNH}}_2$- used for removal of acidic proton

2. ${\mathrm{CH}}_3\mathrm{Br}$- addition of alkyl halide to add one more carbon in the chain

3. ${\mathrm{H}}_2$, Lindlar’s catalyst – addition of from same side

Hence the formation of Cis-2-butene occurs.