Naming Hydrocarbons by hedongchenchen


									Naming Cyclic Hydrocarbon
and Aromatic compounds
                          ORGANIC COMPOUNDS

                                            HYDROCARBON DERIVATIVES
                                           - alcohols - ethers - esters
                                           - amines - carboxylic acids
     ALIPHATIC                  AROMATIC
                               e.g. benzene

        ACYCLIC                                                   CYCLIC
  - Straight chains                                       - Rings

                                           CYCLOALKANES             CYCLOALKENES
   all C-C   at least 1   at least 1 CC
single bonds C=C double     triple bond    all C-C single bonds     at least 1 C=C
             bond                                                   double bond
• Cycloalkanes a type of alkane
  hydrocarbon which contains a closed ring
  of carbon atoms
• Saturated because they contain maximum
  number of atoms per carbon (4 bonds)
• Non-Polar
• General formula is CnH2n
Name           Molecular Structural Skeletal
               formula   formula    formula



• Cycloalkenes is a type of alkene
  hydrocarbon which contains a closed ring
  of carbon atoms
• Unsaturated
• Non-Polar
• General formula is CnH2n-2
Name           Molecular Structural Skeletal
               formula   formula    formula



Naming Cyclic Hydrocarbon
Rules for naming Cyclic compounds
Step 1:
      -Determine the root – count the number of
       carbons in the ring
      - Add “cyclo” in front the root
Step 2: Determine the suffix ( -ane or -ene)
Step 3: Start numbering the carbon that has a side
      chain attach to it and give lowest possible
      number to the branch
Step 4: Determine the prefix
Naming Cyclic Hydrocarbon
                             Since there is
                             only one side
                             chain, do not
                             need to number
                             the position

       ethyl cyclohept ane
Naming Cyclic Hydrocarbon
Example: More then one Branch
Start numbering at the carbon that contains the branches

Naming Cyclic Hydrocarbon
Example: Cycloalkene
Start numbering the carbon at the double bond

                                   If only one
                                   double bond
                                   don’t need
                                   to number it.

           2-methyl Cyclobut ene
Naming Cyclic Hydrocarbon
Example: Cyclic hydrocarbons as a branch
If the straight chain that is attach to the ring has more
carbons then the ring, then make the cyclo group the
side chain.

              1-cyclobutyl pentane
Aromatic Hydrocarbons
• Based on the benzene molecule
• General formula ( C6H6)
• Benzene has the structure

• Bonds are actually not double or single, they are
  a mix between double and single and are much
  more stable
• Don’t go through same reactions as double bonds
Aromatic Hydrocarbons
• Resonance structure of benzene:

• Electrons in the bonds are “shared,” or
  delocalized, over the whole molecule
Naming Aromatic Hydrocarbons
Number carbons in benzene ring by beginning with the
branch that has the highest priority ( higher #C)
1. Name any branches that are attached to the     ring,
   giving them position numbers (if there’s only one
   branch, no number is written).
2. Place the branch numbers and names as a prefix
   before the root “benzene”.
Naming Aromatic Hydrocarbons

           propyl benzene
Naming Aromatic Hydrocarbons
 Prefixes instead of numbers
 When a benzene ring has only 2 branches, the
 following prefixes are used
Prefix      Example        Name
When two or more molecules have the same
molecular formula but different structures
formula they are called isomers.
• There are two types of isomers:
  • Structural isomers have same
    molecular formula but the atoms are
    bonded together in different orders
  • Stereoisomer isomers have the
    molecular formula and sequence of
    bonded atoms, which differ only in the
    three-dimensional orientations of their
    atoms in space
Structural Isomers:
What are the structural isomers of C4H10?

CH3 CH2 CH2 CH3                CH3 CH CH3
     Butane (C4H10 )          2-methylpropane (C4H10)
 Structural Isomers:
 What are the structural isomers of C4H8?

   CH2 CH CH2 CH3                CH3 CH CH CH3
      1-butene                       2-butene
      CH3             CH2 CH2
                                            CH2 CH
CH2 C     CH3         CH2 CH2                      CH3
2-methylpropene      cyclobutane methylcyclopropane
• Stereoisomerism about double bonds occur
  because rotation about the double bond is
  restricted, keeping the branch's fixed
  relative to each other
• Double bond stereochemistry are described
  using either cis ( on the same side) or trans
  (opposite side )

 cis-2-butene            trans-2 butene
• Practice naming the cyclic and aromatic
  ring from the handout and use tiles to
  check answer

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