Suggest a reagent and a reactant that could be used to form the following molecules by conjugate addition of a cuprate. There can be multiple possibilities.
(b)

Verified step by step guidance

1. Identify the target molecule as a cyclohexanone derivative with a cyclopropyl group attached at the beta position relative to the carbonyl group.
2. Recognize that conjugate addition (1,4-addition) involves the addition of a nucleophile to the beta position of an alpha, beta-unsaturated carbonyl compound.
3. Select an appropriate alpha, beta-unsaturated carbonyl compound as the starting material. In this case, cyclohexenone can be used as it has the necessary unsaturation for conjugate addition.
4. Choose a suitable cuprate reagent for the conjugate addition. A common choice is a lithium diorganocuprate, such as lithium cyclopropylcuprate (LiCu(C3H5)2), which can deliver the cyclopropyl group to the beta position.
5. Outline the reaction: The lithium cyclopropylcuprate will add to the beta position of cyclohexenone, resulting in the formation of the desired cyclohexanone derivative with a cyclopropyl group at the beta position.

Key Concepts

Conjugate Addition

Conjugate addition refers to the nucleophilic addition of a reagent to the β-carbon of an α,β-unsaturated carbonyl compound. This reaction typically involves the addition of a nucleophile to the double bond, resulting in the formation of a new carbon-carbon bond. Understanding this mechanism is crucial for predicting the products of reactions involving cuprates and unsaturated carbonyls.

Cuprates

Cuprates are organocopper reagents, commonly represented as R2CuLi, where R is an organic group. They are powerful nucleophiles used in organic synthesis, particularly for conjugate additions to α,β-unsaturated carbonyl compounds. Their ability to selectively add to the β-position makes them valuable for forming complex molecules in a controlled manner.

Reagent and Reactant Selection

Choosing the appropriate reagent and reactant is essential for successful conjugate addition. The reactant is typically an α,β-unsaturated carbonyl compound, while the reagent is a cuprate that can provide the necessary nucleophile. Understanding the structure and reactivity of both components helps in predicting the outcome of the reaction and the formation of desired products.