Question

Oxidation of a dithiol such as hexane-2,5-dithiol forms a six-membered ring containing a disulfide group as part of the ring. Draw the structure of this cyclic disulfide (Hint: Draw the starting compound in line structure format first).

Short answer

A six-membered ring with a disulfide bond between the 2nd and 5th carbons.

Step-by-step solution

Understand the Starting Compound

We begin with the compound hexane-2,5-dithiol, which consists of a six-carbon chain with thiol groups (-SH) attached to the 2nd and 5th carbon atoms. This is the starting structure before oxidation.

Draw the Initial Structure

Draw hexane-2,5-dithiol in line structure format. The main chain is depicted as a straight line of six interconnected points (representing carbon atoms). The thiol groups (-SH) are attached to the second and fifth carbon atoms along this chain.

Overview of Oxidation Reaction

When hexane-2,5-dithiol undergoes oxidation, the two thiol (-SH) groups lose their hydrogen atoms and form a disulfide bond (-S-S-), connecting them and closing the chain into a ring.

Draw the Cyclic Disulfide Structure

Illustrate the six-membered ring, emphasizing the new disulfide bond formed between the sulfur atoms of the 2nd and 5th carbons. The resulting ring structure should show a sequence of carbon atoms with a -S-S- linkage within the ring.

Key concepts

Dithiol Oxidation

In organic chemistry, dithiols are molecules that contain two thiol groups, which are sulfur-containing functional groups (-SH). The process of dithiol oxidation involves the transformation of these two thiol groups into a disulfide bond (-S-S-). During oxidation, each sulfur atom in the thiol groups loses a hydrogen atom. This loss results in the formation of a disulfide bridge that connects the two sulfur atoms.
This transformation is fundamental in many organic reactions, serving as a key step in the formation of stable structures such as rings. Hexane-2,5-dithiol is a prime example used to understand this concept. By initially having thiol groups at specific positions, the oxidation process enables the formation of larger and more complex molecular structures, improving the compound's stability.

Cyclic Disulfide Formation

Cyclic disulfides are created when a linear or open molecule containing thiol groups undergoes oxidation to form a ring. Hexane-2,5-dithiol, when oxidized, creates a cyclic disulfide. This involves forming a new bond between the sulfur atoms of the thiol groups.

• The formation of cyclic disulfides begins with the oxidation of the thiol groups.
• Next, each thiol group releases a hydrogen atom and the two sulfur atoms bond together.
• This results in a closed-ring structure featuring the disulfide bond, creating a stable 6-membered ring in the case of hexane-2,5-dithiol.

This type of reaction highlights the importance of atom positioning within the molecule, as it dictates the ability to form cyclic structures through the creation of disulfide bridges.

Disulfide Bond

Disulfide bonds are a crucial aspect in the study of organic chemistry and biochemistry. They consist of two sulfur atoms bonded together, often as a result of the oxidation of thiol groups. The formation of disulfide bonds significantly influences the stability and functionality of proteins and other organic compounds.

• These bonds can be found in both intramolecular settings, forming loops and closed-ring structures, as well as intermolecularly, linking separate molecules together.
• In cyclic disulfides, like the one formed from hexane-2,5-dithiol, the disulfide bond is part of a closed loop, enhancing stability and rigidity.

Understanding disulfide bonds allows scientists to manipulate molecular structures intentionally, which is especially critical in areas like drug design and protein engineering.

Organic Chemistry Education

Learning about reactions like dithiol oxidation and the formation of cyclic compounds helps students deepen their understanding of organic chemistry. These concepts showcase the interaction between different functional groups and explain how molecular changes occur through specific reactions.
When studying concepts like cyclic disulfides, students gain important insights into:

• The role of oxidation reactions in organic chemistry transformations.
• How specific molecular conformations can lead to different structural outcomes, influencing chemical behavior.
• The practical applications of these reactions in fields like pharmaceuticals, where molecular shape is crucial for function.

Organic chemistry education combines theoretical knowledge with practical applications, empowering students to explore complex chemical transformations and become adept problem solvers in real-world scenarios.