Question

Draw the product when each compound is treated with either (CH₃)₂CuLi , followed by H₂O , HC$\equiv$CLi , followed by H₂O .

a.

b.

c.

Short answer

Answer

The addition products formed are shown below:

a.

b.

c.

Step-by-step solution

Step-by-Step Solution Step 1: Determination of 1,2- addition reaction

The 1,2-addition reaction takes place when you use an organolithium reagent in the case of $\mathrm{\alpha },\mathrm{\beta }$ unsaturated carbonyl compounds.

It directly attacks the carbonyl carbon center, known as the 1,2-addition attack.

Determination of 1,4- addition reaction

The 1,4-addition reaction takes place when an organocuprate reagent is used in the case of $\mathrm{\alpha },\mathrm{\beta }$ unsaturated carbonyl compounds. It attacks the alkene carbon of the fourth position from the carbonyl oxygen, known as the 1,4-addition attack.

The products formed in the given reactions

The addition products of compound a. are:

Reaction of compound b.

The addition products of compound b. are:

Reaction of compound b.

The addition products of compound c. are:

Reaction of compound c.