Predict the products of the following reactions:
(d)

Verified step by step guidance

1. Step 1: Analyze the given reactants and reagents. The starting compound is butan-2-one, a ketone. The first set of reagents, KCN and HCN, indicates a cyanohydrin formation reaction. The second reagent, LiAlH4, is a strong reducing agent used to reduce functional groups such as nitriles to primary amines.
2. Step 2: Understand the mechanism of cyanohydrin formation. In the presence of KCN and HCN, the ketone undergoes nucleophilic addition. The cyanide ion (CN⁻) attacks the carbonyl carbon of butan-2-one, forming a tetrahedral intermediate. Protonation by HCN leads to the formation of a cyanohydrin, which contains both a hydroxyl (-OH) group and a nitrile (-CN) group.
3. Step 3: Predict the structure of the cyanohydrin product. The carbonyl group of butan-2-one is converted into a hydroxyl group, and a nitrile group is added to the same carbon. The resulting compound is 2-hydroxy-2-methylbutanenitrile.
4. Step 4: Understand the reduction step with LiAlH4. LiAlH4 reduces the nitrile group (-CN) in the cyanohydrin to a primary amine (-CH₂NH₂). The hydroxyl group (-OH) remains unchanged during this reduction.
5. Step 5: Predict the final product. After the reduction step, the final product is 2-hydroxy-2-methylbutanamine, which contains both a hydroxyl group and a primary amine group on the same carbon.

Key Concepts

Nucleophilic Addition

Nucleophilic addition is a fundamental reaction mechanism in organic chemistry where a nucleophile attacks an electrophilic carbon atom, typically in a carbonyl group. In this case, KCN and HCN act as nucleophiles that add to the carbonyl carbon of butan-2-one, leading to the formation of a cyanohydrin intermediate.

Reduction Reactions

Reduction reactions involve the gain of electrons or the decrease in oxidation state of a molecule. In the second step of the reaction, LiAlH4 is a strong reducing agent that reduces the cyanohydrin formed in the first step to an alcohol, specifically converting the nitrile group into a primary amine or alcohol, depending on the reaction conditions.

Functional Group Transformation

Functional group transformation refers to the conversion of one functional group into another through chemical reactions. In this reaction sequence, butan-2-one undergoes transformation first into a cyanohydrin and then into an alcohol, showcasing how different reagents can modify the functional groups present in organic molecules.