Using your roadmaps as a guide, show how to convert cyclohexane into adipoyl dichloride. Show all reagents and all molecules synthesized along the way. O=C(Cl)CCCCC(=O)Cl Cyclohexane Adipoyl dichloride

The transformation of cyclohexane into cyclohexene is a type of alkene synthesis called dehydrogenation, where two hydrogen atoms are removed from cyclohexane. This step is crucial because it forms an alkene, which is a more reactive intermediate for further chemical transformations.

The process uses an alkaline potassium permanganate (KMnO₄) solution, often in a basic medium. The reaction typically requires heat to proceed effectively, and it is commonly conducted at reflux temperature, which ensures the reaction mixture is heated to boiling without loss of material. Although KMnO₄ is an oxidizing agent, under controlled conditions it selectively removes hydrogen atoms to produce the alkene without further oxidation.

Once cyclohexene is prepared, the next step is to perform a dihydroxylation reaction to create 1,6-hexanediol. This involves the addition of two hydroxyl (-OH) groups across the double bond of cyclohexene, effectively transforming the unsaturated alkene into a diol.

The reaction utilizes osmium tetroxide (OsO₄) as a catalyst. Osmium tetroxide is ideal for this reaction due to its ability to add to the double bond with great stereospecificity, generally leading to the formation of a cis-diol (both -OH groups on the same side). Subsequent treatment with hydrogen peroxide (H₂O₂) as an oxidizing agent assists in the re-oxidation of the osmium catalyst, which is coordinated by the diol.

The conversion of 1,6-hexanediol to adipic acid entails an oxidation process that cleaves the carbon chain at the secondary alcohol (C-OH) groups, transforming them into carboxylic acid (-COOH) groups. This key step is fundamental in polymer chemistry for the production of nylon, as adipic acid is a precursor to nylon-6,6.

Potassium permanganate (KMnO₄) is once more the reagent of choice due to its robust oxidizing ability. The reaction takes place under acidic conditions, often provided by dilute sulfuric acid (H₂SO₄), which helps to stabilize the permanganate ion. The use of an oxidative environment is critical to ensure the complete conversion of the diol to the dicarboxylic acid.

The last stage of this chemical odyssey is converting adipic acid into adipoyl dichloride, a valuable intermediate for the synthesis of polyamides like nylon. The formation of adipoyl dichloride from adipic acid involves a reaction known as acyl chlorination.

The reagent thionyl chloride (SOCl₂) is employed for its efficiency in replacing the carboxylic acid's hydroxyl groups with chloride. This step plays a vital role because the chloride (Cl) substituents are excellent leaving groups for subsequent reactions in nylon synthesis. Moreover, the reaction byproduct, sulfur dioxide (SO₂), is a gas that escapes the reaction mixture, driving the equilibrium towards the formation of the desired dichloride.