Predict the products of the following reactions:
(e)
(f)

Verified step by step guidance

1. Step 1: Analyze the reagent DIBAL-H (Diisobutylaluminum hydride). DIBAL-H is a selective reducing agent that reduces esters and lactones to aldehydes under controlled conditions (low temperature, -78°C). It does not reduce the carbonyl group completely to an alcohol in this case.
2. Step 2: For reaction (e), identify the functional groups in the starting material. The molecule contains an ester group (O=C-OCH₃) and a double bond in the alkyl chain. DIBAL-H selectively reduces the ester group to an aldehyde without affecting the double bond.
3. Step 3: For reaction (f), identify the functional groups in the starting material. The molecule contains a lactone (cyclic ester). DIBAL-H selectively reduces the lactone to an aldehyde, opening the ring structure in the process.
4. Step 4: Consider the reaction conditions. The reaction is performed at -78°C, which ensures selective reduction to aldehydes without over-reduction to alcohols. The addition of water (H₂O) in the second step quenches the reaction and hydrolyzes the aluminum complex formed during reduction.
5. Step 5: Predict the products. For reaction (e), the ester group is reduced to an aldehyde, and the double bond remains intact. For reaction (f), the lactone is reduced to an aldehyde, resulting in a linear molecule with an aldehyde group at one end.

Key Concepts

Reaction Mechanisms

Understanding reaction mechanisms is crucial in organic chemistry as they describe the step-by-step process by which reactants transform into products. This includes identifying intermediates, transition states, and the movement of electrons. Familiarity with mechanisms helps predict the outcome of reactions and the stability of products formed.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. Recognizing functional groups allows chemists to predict reactivity patterns and the types of reactions that can occur, which is essential for determining the products of a given reaction.

Stereochemistry

Stereochemistry involves the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. It is important for predicting the products of reactions, especially in cases where chirality or geometric isomerism plays a role. Understanding stereochemical outcomes can significantly influence the properties and reactivity of organic compounds.