Q11P - Organic Chemistry (Mcmurry)

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.

Step-by-Step Solution

Answer

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.