Corrections from Wednesday

1
Corrections from Wednesday

• Alkenes
• always give double bond lowest numbers possible
• Cis and Trans
• Place cis- or trans- in front of name, i.e.
• trans-4-methyl-2-pentene
• Your Book on pg. 1023 is incorrect when it says
• 4-methyl-trans-2-pentene
• Hyphens
• No hyphen before root name 3-methylcyclohexene

No Hyphen
2
Alkene Nomenclature

• Similar to alkanes, except
• Root hydrocarbon name ends in ene
• Location of the double bond is indicated
• add the lowest-numbered double-bound carbon
  before root name
• Give double bond the lowest possible numbers
• The double bond must be included in parent chain

1-butene
2-butene
3

• Draw the structure for 4-methyl-2-pentene.
• Correction This is the correct name for the
  structure. Ensure that the double bond has the
  lowest possible numbers.
• However, you can add cis- or trans-
• above trans-4-methyl-2-pentene
• cis-4-methyl-2-pentene ?

4
Cylic Alkene Nomenclature

• For cyclic alkenes, place double bond between C1
  and C2
• Dont need to indicate position of double bond in
  name
• Ex Draw 3-methylcyclohexene

4-ethylcyclopentene
No Hyphen
5
Alkene Nomenclature Change

• Standard naming, before 1993
• 3-methyl-2-hexene
• In 1993, IUPAC recommended a change
• 3-methylhex-2-ene
• Your book, and this course, uses old system
• 3-methyl-2-hexene

6

• Name the following

3
4
5
6
7
1
2
Not numbered 7 ? 1 Double bond has priority
3-Heptene
6-methyl-
cis-
7
Not part of parent Double bond must be in
parent chain

• Name the following
• An approximation for this course
• Choose largest group on each side of the double
  bond
• If these groups are on the same side, cis-

2
3
1
4
5
6
7
2-Heptene
5-methyl-3-propyl-
cis-
8
Alkynes

• Contain a triple bond
• Named like alkenes, except suffix yne
• Example Name the following

1 2 3 4
Give the triple bond the lowest possible number
4-methyl-2-hexyne
9
Aromatic Hydrocarbons (21.3)

• Cyclic unsaturated hydrocarbons with delocalized
  p electrons
• Simplest example is benzene

Fig 21.11 pg 1026
10
Naming Benzene Derivatives

• Like other cyclic hydrocarbons
• use root name benzene
• When benzene is a substituent, called phenyl

11
Alternate Benzene Naming

• Ortho next to
• Meta one carbon between
• Para across

Fig 21.12 pg 1027
12

• Draw the structure for
• 1-ethyl-3-methylbenzene
• Another name m-ethylmethylbenzene

13

• Common name of aromatic compound can serve as
  root name

Toluene
2-methyl-1,3,5-trinitrobenzene or 2,4,6-trinitroto
luene (TNT) (set methyl carbon as 1)
14
Hydrocarbon Derivatives (21.4)

• Hydrocarbon backbones often have atoms other than
  carbon and hydrogen
• These functional groups exhibit characteristic
  chemistry

Cholesterol
Functional Group
15
Know how to Recognize All functional groups in
your book, table 21.4 Name Halocarbons Alcohols A
ldehydes Ketones Carboxylic Acids
16

• What functional groups are present in
  acetaminophen?

Secondary Amine
Ketone
Alcohol
17
Tertiary Amine
Ester
Primary Amine

• What functional groups are present in procaine
  (novocaine)?

18
Naming Halogen Substituents
Use like alkyl substituents (methyl- )

• F fluoro-
• Cl chloro-
• Br bromo-
• I iodo-

19
Naming Hydrocarbon Derivatives

• Select parent chain
• Longest chain that contains the functional group
• Name parent chain with suffix to reflect
  functional group (replace e ending with suffix)
• Number parent chain
• Place functional group closest to carbon 1
• Only number carbon atoms!
• Specify location of functional group if necessary
• Add substituents (like before)

20
Parent Chains

• (root name) (letters for single, multiple bond)
  (suffix)
• an en yn
• Hydrocarbons e (i.e. hexane hexene )
• Alcohols ol (i.e. hexanol hexenol )
• Aldehydes al
• Ketones one
• Carboxylic Acids oic acid