To practice working through the early parts of a multistep synthesis, devise syntheses of
(a) pentan-3-one from alcohols containing no more than three carbon atoms.

Verified step by step guidance

1. Step 1: Identify the target molecule, pentan-3-one, which is a ketone with the carbonyl group on the third carbon of a five-carbon chain. This will guide the synthesis strategy.
2. Step 2: Recognize the constraint that the starting materials must be alcohols containing no more than three carbon atoms. This means you need to build the five-carbon chain using smaller alcohols.
3. Step 3: Select appropriate alcohols as starting materials. For example, ethanol (CH₃CH₂OH) and propanol (CH₃CH₂CH₂OH) are suitable candidates because they each contain fewer than three carbons.
4. Step 4: Devise a strategy to combine the alcohols into a five-carbon chain. This can involve converting the alcohols into reactive intermediates, such as alkyl halides, followed by a coupling reaction like the Grignard reaction or an alkylation reaction.
5. Step 5: Once the five-carbon chain is formed, oxidize the alcohol group on the third carbon to a ketone using an oxidizing agent such as PCC (pyridinium chlorochromate) or Jones reagent. Ensure the reaction conditions are controlled to avoid overoxidation.

Key Concepts

Multistep Synthesis

Multistep synthesis involves a series of chemical reactions that transform starting materials into a desired product through intermediate compounds. Understanding this concept is crucial for planning the sequence of reactions needed to convert simple alcohols into more complex molecules like pentan-3-one. Each step must be carefully designed to ensure that the desired functional groups are introduced and that the overall yield is maximized.

Functional Group Transformation

Functional group transformation refers to the process of converting one functional group into another during a chemical reaction. In the context of synthesizing pentan-3-one, it is essential to know how to manipulate alcohols, which contain hydroxyl (-OH) groups, into ketones, which have a carbonyl (C=O) group. This transformation often requires specific reagents and conditions to achieve the desired outcome.

Carbon Skeleton Rearrangement

Carbon skeleton rearrangement is a key concept in organic chemistry that involves the reorganization of the carbon framework of a molecule during a reaction. When synthesizing pentan-3-one from smaller alcohols, understanding how to effectively rearrange carbon chains is vital. This may involve reactions such as dehydration or oxidation, which can alter the position of functional groups and the overall structure of the molecule.