Predict the product of the following reductions.
(b)

Verified step by step guidance

1. Identify the functional group in the given compound that is subject to reduction. In this case, the compound contains an amide group, characterized by the carbonyl group (C=O) bonded to a nitrogen atom (N).
2. Recognize the reducing agent used in the reaction. Lithium aluminum hydride (LiAlH4) is a strong reducing agent, commonly used to reduce amides to amines.
3. Understand the mechanism of reduction with LiAlH4. The hydride ions (H-) from LiAlH4 attack the carbonyl carbon of the amide, leading to the formation of an intermediate that eventually results in the removal of the oxygen atom and the conversion of the carbonyl group to a methylene group (CH2).
4. Consider the stereochemistry of the reaction. The stereochemistry at the chiral center adjacent to the amide group should be preserved during the reduction process, as LiAlH4 does not affect the stereochemistry of the existing chiral centers.
5. After the reduction step, the reaction is quenched with water (H3O+), which helps to neutralize any remaining LiAlH4 and stabilize the newly formed amine product. The final product will be an amine with the same carbon skeleton as the starting material, but with the carbonyl group reduced to a methylene group.

Key Concepts

Reduction Reactions

Reduction reactions in organic chemistry involve the gain of electrons or hydrogen, or the loss of oxygen by a molecule. These reactions typically convert carbonyl compounds, alkenes, or alkynes into alcohols or alkanes. Understanding the type of functional groups present in the substrate is crucial for predicting the outcome of the reduction.

Common Reducing Agents

Various reducing agents are used in organic chemistry, including lithium aluminum hydride (LiAlH4), sodium borohydride (NaBH4), and hydrogen gas (H2) in the presence of a catalyst. Each reducing agent has specific reactivity and selectivity, influencing which functional groups are reduced and to what extent. Familiarity with these agents helps in predicting the products of reduction reactions.

Stereochemistry of Products

Stereochemistry refers to the spatial arrangement of atoms in molecules and how this affects their chemical behavior. During reduction reactions, the stereochemistry of the starting material can influence the stereochemical outcome of the product, especially in cases involving chiral centers. Recognizing potential stereoisomers is essential for accurately predicting the final products of reductions.