Organic Chemistry ch' 21

1
Organic Chemistry (ch. 21)

• Carbon has unique ability to form long chains of
  carbon atoms
• Study of these molecules is called organic
  chemistry
• Study of these molecules in a biological setting
  biochemistry

2
Representing Organic Molecules

• Carbon always makes 4 bonds
• (Nitrogen makes 3, oxygen makes 2)
• Example Butane
• Both ends of every line segment are carbon atoms
• Hydrogens are assumed but not shown
• All other atoms shown (N, O, S, etc)

3

• Example acetone CH3COCH3
• Example n-propylamide CH3CH2CONH2

4
Vocabulary

• Hydrocarbons compounds composed of carbon and
  hydrogen
• Saturated hydrocarbons all single bonds
• a.k.a alkanes
• Unsaturated hydrocarbons have double bonds
• Normal, straight-chain, unbranched hydrocarbons
  no branching

5
Alkanes

• Example n-pentane, 2-methylbutane
• These are structural isomers of each other (same
  atoms, different bonds)
• All alkanes with 4 or more carbons have
  structural isomers

6

• Note all bonds in alkanes are 109.5, even if
  not drawn that way

Fig. 21.3 pg 1016
7
Nomenclature!

• Find longest straight carbon chain
• The number of carbons gives the root name for the
  hydrocarbon
• (prefix)(ane)

• meth-
• eth-
• prop-
• but-
• pent-
• hex-
• hept-
• oct-
• non-
• dec-

• Number the carbons

8
Number the Carbons

• Number the carbons of the longest straight chain,
  to specify where a substituent is
• Minimize the value of numbers used

9
Nomenclature!

• Find longest straight carbon chain
• The number of carbons gives the root name for the
  hydrocarbon
• (prefix)(ane)

• meth-
• eth-
• prop-
• but-
• pent-
• hex-
• hept-
• oct-
• non-
• dec-

• Number the carbons

• Name substituents

10
Substituents

• If alkane groups are substituents, use same
  prefix with yl
• (prefix)(yl) methyl, ethyl, propyl.
• If multiple, identical substituents, use di- or
  tri-
• Alphabetize nonidentical substituents
• Naming other types of subtstituents will be
  discussed later

11
21.2
12
Nomenclature!

• Find longest straight carbon chain
• The number of carbons gives the root name for the
  hydrocarbon
• (prefix)(ane)

• meth-
• eth-
• prop-
• but-
• pent-
• hex-
• hept-
• oct-
• non-
• dec-

• Number the carbons
• Name substituents

• Make name

(number)-(substituent)(prefix)(ane)