Show how you would accomplish the following syntheses.
c. hexan-1-ol → 2-hydroxyheptanoic acid

Verified step by step guidance

1. Step 1: Begin by converting hexan-1-ol into a primary alkyl halide. This can be achieved through a reaction with thionyl chloride (SOCl₂) or phosphorus tribromide (PBr₃), which replaces the hydroxyl group (-OH) with a halogen (e.g., -Cl or -Br). This step prepares the molecule for further functionalization.
2. Step 2: Perform a nucleophilic substitution reaction to elongate the carbon chain. React the alkyl halide with cyanide ion (CN⁻) in the presence of a polar aprotic solvent like DMSO. This introduces a nitrile group (-C≡N) at the end of the chain, extending the molecule by one carbon atom.
3. Step 3: Hydrolyze the nitrile group to convert it into a carboxylic acid (-COOH). This can be accomplished using acidic or basic hydrolysis. For acidic hydrolysis, use H₃O⁺ (acidic water) and heat. For basic hydrolysis, use NaOH followed by acidification. This step yields heptanoic acid.
4. Step 4: Introduce the hydroxyl group (-OH) at the second carbon position. This can be achieved through selective oxidation of the heptanoic acid using a reagent like selenium dioxide (SeO₂) or by employing a hydroxylation reaction with a suitable catalyst.
5. Step 5: Verify the structure of the final product, 2-hydroxyheptanoic acid, using spectroscopic techniques such as NMR or IR to ensure the synthesis was successful and the functional groups are correctly positioned.

Key Concepts

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In this synthesis, understanding the functional groups involved, such as alcohols and carboxylic acids, is crucial for predicting the reactivity and transformation of hexan-1-ol into 2-hydroxyheptanoic acid.

Oxidation and Reduction Reactions

Oxidation and reduction reactions involve the transfer of electrons between substances, leading to changes in oxidation states. In the conversion of hexan-1-ol to 2-hydroxyheptanoic acid, oxidation of the alcohol group to a carboxylic acid is a key step, highlighting the importance of understanding these redox processes in organic synthesis.

Synthesis Pathways

Synthesis pathways refer to the series of chemical reactions that transform one compound into another. For the synthesis of 2-hydroxyheptanoic acid from hexan-1-ol, identifying the appropriate reagents and reaction conditions, such as oxidation agents, is essential for successfully navigating the pathway from the starting material to the desired product.