Suggest the most appropriate reagent for each synthesis, and explain your choice.
(c)

Verified step by step guidance

1. Step 1: Analyze the transformation. The starting material is a ketone with a methoxy group (-OCH3) attached to the carbonyl carbon. The product is an alcohol (-CH2OH) where the methoxy group has been replaced by a hydroxymethyl group.
2. Step 2: Recognize the type of reaction. This transformation involves the reduction of the ester functional group (-COOCH3) to a primary alcohol (-CH2OH). This suggests the use of a reducing agent.
3. Step 3: Identify the appropriate reagent. Lithium aluminum hydride (LiAlH4) is a strong reducing agent commonly used to reduce esters to primary alcohols. It selectively reduces the ester group without affecting the double bond in the molecule.
4. Step 4: Explain the mechanism. LiAlH4 donates hydride ions (H-) to the carbonyl carbon of the ester, breaking the C=O bond and forming an intermediate alkoxide. Subsequent protonation during workup converts the alkoxide to the alcohol (-CH2OH).
5. Step 5: Note reaction conditions. The reaction typically requires an anhydrous solvent like ether and careful handling due to the reactivity of LiAlH4. After reduction, the reaction mixture is quenched with water or an acid to complete the conversion to the alcohol.

Key Concepts

Reagents in Organic Synthesis

Reagents are substances used in chemical reactions to facilitate the transformation of reactants into products. In organic synthesis, the choice of reagent is crucial as it determines the reaction pathway, the functional groups involved, and the overall yield of the desired product. Understanding the properties and reactivity of various reagents is essential for selecting the most appropriate one for a specific synthesis.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. Identifying the functional groups present in the starting materials and the desired product is vital for determining which reagents will effectively facilitate the necessary transformations. Knowledge of common functional groups helps predict reactivity and selectivity in organic reactions.

Reaction Mechanisms

A reaction mechanism is a step-by-step description of the process by which reactants are converted into products. Understanding the mechanism provides insight into how and why certain reagents are chosen, as it reveals the intermediates formed and the energy changes involved. This knowledge is essential for predicting the outcomes of reactions and for troubleshooting synthesis problems.