PP 38: Aromatic Hydrocarbons
Aromatic Hydrocarbons:
• Hydrocarbons with 4n+2 p electrons
• Compounds with an odd # of double bonds at every other carbon
• The double bonds must lie in a flat plane
• Most contain benzene rings or related systems
• All have an aroma (Most are pleasant)
• Also called: Arenes
Aromatic Hydrocarbons:
• Hydrocarbons with 4n p electrons
• Hydrocarbons other than aromatic hydrocarbons
• The most common aromaric compound:
Drill: Name:
Draw: Propylbenzene:
Naming Substituted arenes: (Same as any cyclic hydrocarbon)
• Use the same rules as for cyclic compounds
• Special exception will follow
1) apply numbers
2) name branches alphabetically
3) name cycle
2,3-diethyl-1-propylbenzene
Special Exceptions: Some aromatic compounds have common names.
Methylbenzene: (Toluene):
1,4 – dimetrhylbenzene: (para-xylene)
Special Naming for Disubstituted Benzene Rings: (two groups attached to a benzene ring)
 1,2 – disubstituted benzene: ortho-disubstituted benzene
 1,3 – disubstituted benzene: meta-disubstituted benzene
 1,4 – disubstituted benzene: para-disubstituted benzene
Example: 1,2 – dimethylbenzene: para – xylene (above)
Name:
Naming Benzene as a branch: Phenyl Group
Example: (a benzene ring attached to pyruvate): Phenylpyruvate
Drill: Name:
Draw & name a compound with 8 carbons, 1, branch, 1 double bond, & 1 triple bond:
Draw & Name all the possible isomers for C6H10:
Name each of the following:
Draw each of the following:
• cis-6-ethyl-2,3-dimethyl-5-phenyl-4-octene
• all trans-3,4,5,6,7,8-hexamethyldeca-2,4,6,8-tetraene
Draw & name all the possible isomers of C7H14:
Draw & name all the possible isomers of C7H12:
Test Review:
Draw each of the following:
•
•
trans,cis-4-ethyl-3-methylocta-2,5-diene
cis-6-methyl-4-phenylhepta-4-en-2-yne
Draw & Name at least 10 isomers of: C6H10: