Naming Bicyclic Compounds

Types of Bicyclic Compounds

• Bridged Bicyclics
• Fused Bicyclics
• Spiro Bicyclics

Previous Topics Covered

• Naming alkanes
• Naming complex substituents

Key Concepts

• Special rules for naming bicyclic compounds.
• Different sets of rules apply to bridged, fused, and spiro bicyclic compounds.

Bridged Bicyclic Compounds

• Recognized by a sideways perspective drawing.

• Consist of multiple rings sharing two or more common carbon atoms (bridgehead carbons).

• Naming Rules:

  • Count the total number of carbon atoms: parent name is based on this number (e.g., bicyclooctane for 8 carbons).
  • Use brackets to indicate the number of carbons in each path between bridgehead carbons, presenting them in descending order (e.g., bicyclo[3.2.1]octane).
  • For substituted bicyclics, number the carbon atoms starting from a bridgehead and prioritizing the longest path first.

• When substituents are present:

  • Assign numbers to locate substituents by choosing the numbering path that gives the lowest possible numbers.

Fused Bicyclic Compounds

• Similar to bridged bicyclics but with bridgehead carbons directly bonded.
• Third number in the bracket notation is always zero, e.g., bicyclo[4.2.0]octane.

Spiro Bicyclic Compounds

• Feature two rings that share a single common carbon (spiro carbon).
• Naming Rules:
  • Identify the spiro carbon.
  • Count the number of carbons in each path from the spiro carbon back to itself.
  • Numbers are listed in ascending order, e.g., spiro[4.5]decane.
  • When substituents are present, do not start numbering at the spiro carbon.
  • Choose a method such that substituents receive the lowest possible numbers, starting with the smaller set of carbons.

Importance and Variability in Curriculum

• Not all students may learn about bicyclic compounds.
• Some professors/textbooks might exclude certain types or omit substituent numbering altogether.
• Understanding of this topic is crucial for those who are required to learn it.

Future Topics

• Conformations of alkanes.
• Nomenclature of functional groups throughout the course.
• Functional groups may have different suffixes or prefixes based on their priority in the molecule.

Additional Resources

• Practice problems and study guides available on Chad’s premium course website.

Note: These notes are intended to provide a concise overview of the lecture content on naming bicyclic compounds and serve as a study reference.