Question

Name the following compounds: (a) C1=CC2CCC1C2 (b) FC1(F)CC2CC21 (c) OC1CC2C=CC1C2

Short answer

(a) Norbornene, (b) 1,1-Difluorobicyclo[1.1.0]butane, (c) Norcamphor.

Step-by-step solution

Title - Identify the Structure of Compound (a)

Compound (a) is given as C1=CC2CCC1C2. Identify the structure and determine the chemical name. This compound is bicyclo[2.2.1]hept-2-ene, commonly known as norbornene.

Title - Analyze the Structure of Compound (b)

Compound (b) is given as FC1(F)CC2CC21. This compound is determined to be a bicyclic compound with two fluorine substituents. The correct name for this compound is 1,1-difluorobicyclo[1.1.0]butane.

Title - Determine the Name of Compound (c)

Compound (c) is given as OC1CC2C=CC1C2. Identify the structure and determine the chemical name. This compound is bicyclo[2.2.1]hept-5-en-2-one, commonly known as norcamphor.

Key concepts

Bicyclic Compounds

Bicyclic compounds are organic compounds that contain two connected rings. These rings can be fused together in various ways, and the number of atoms in each ring can vary. Understanding the structure of bicyclic compounds is essential in organic chemistry. The connection between the rings is called a bridge. For example, in the given compound bicyclo[2.2.1]hept-2-ene, the numbers in the brackets indicate the number of carbon atoms in each bridge, excluding the shared bridgehead carbon atoms.
When numbering a bicyclic compound, start at one bridgehead, proceed along the longest bridge first, then to the next bridge, and finish with the shortest. This ensures a systematic approach and avoids confusion.
Common examples of bicyclic compounds include norbornene and norcamphor. These compounds are found in various natural and synthetic substances and can exhibit interesting chemical properties due to their unique structures.

IUPAC Nomenclature

The International Union of Pure and Applied Chemistry (IUPAC) provides a systematic way to name organic compounds, ensuring that each name is unique and conveys the structure of the molecule. For bicyclic compounds, the IUPAC nomenclature involves:

• Identifying the parent hydrocarbon with the highest number of carbon atoms.
• Numbering the carbon atoms starting from one bridgehead.
• Including numbers in square brackets to indicate the number of atoms in each bridge.
• Naming and numbering any substituents attached to the bicyclic structure.

An example is the compound 1,1-difluorobicyclo[1.1.0]butane. The 'bicyclo' prefix indicates a bicyclic structure, the numbers in brackets show the bridge formation, and the number and type of substituents are given priority in the name.
This method of nomenclature helps in accurately describing complex structures and ensures consistency across scientific discussions and literature.

Structural Identification

Structural identification involves analyzing the chemical structure of a compound to determine its correct name. Begin by visualizing or drawing the molecule based on its chemical formula or SMILES notation.
For example, to identify compound (a) from the given SMILES notation C1=CC2CCC1C2, recognize the ring closure points (the numbers adjacent to 'C'), and how they interconnect. Recognize any double bonds, substituents, or specific functional groups and how they are arranged within the compound.
Each step in the exercise begins with identifying the number of rings, ring junctions (bridgeheads), and any substituents. Implement these steps for compounds like norbornene (bicyclo[2.2.1]hept-2-ene) and norcamphor (bicyclo[2.2.1]hept-5-en-2-one).
Accurate structural identification is crucial for determining the correct chemical names, understanding the reactivity, and deducing physical properties. This forms a foundation for more advanced studies in organic chemistry and molecular identification.