Download General Strategy For Naming Simple Organic Compounds (Bare

1
General Strategy For Naming Simple Organic Compounds (Bare bones summary sheets)
1. Find the highest priority group. These are listed in order of priority in the table of functional groups (next page).
2. Find the longest chain containing the highest priority group. You should know carbon chains of length C1-C19 (listed
in the table).
3. Number the longest chain containing the highest priority group to give the highest priority group the lowest number
possible in numbering the longest chain. For the first seven functional groups, the functional group carbon will be
number 1 (if it is the highest priority group) and the “1” can be omitted, since it is understood that it has to be this way.
4. Usually the highest priority group is named as a suffix at the end of alkane, alk-#-ene or alk-#-yne. The final e is
dropped if the suffix begins with a vowel and it is retained if the suffix begins with a consonant (only two for us,
“nitrile” and “thiol”). A number will be present in front of the suffix name unless its position is unambiguously clear
(e.g. carboxyl groups, aldehydes, nitriles, etc. always = 1, if highest in priority). If there is a C/C pi functional group to
identify (alkene or alkyne), the number in front of its part of the name describes its position (see rule 6 below). If both
a pi bond and a high priority substituent are present, then two (or more) numbers may be necessary, one for each
functionality.
5. Lower priority groups are named with their prefix names and their location numbers based on the numbering of the
parent chain (always true for substituents numbered 12 on the next page). The lower priority substituents should be
listed in alphabetical order. Some parts of prefix names count in this regard and some don't. We will not emphasize
this aspect in this course.
6. Double bonds and triple bonds are named as alk-#-ene or alk-#-yne, respectively. If both are present, name as alk-#en-#-yne. Multiple pi bonds (or other substituents) use the prefixes di, tri, tetra, penta etc. with a number for each
occurrence. In such cases, an "a" is added in front of the numerical prefix for better phonetics. (alka-#,#-diene or alka#,#,#-triyne, alka-#,#-dien-#,#-diyne, etc.)
The essential functional groups to know (for our course) and their prefixes and suffixes are given in the next page. In
this table the term “alkan-#-suffix” is a generic term for any alkane with a functional group suffix, and it must be
replaced with the correct parent stem name based on the number of carbons in the longest chain (C1-C19 for us). If
there is a double bond, the name will change to “alk-#-en-#-suffix and if there is a triple bond, the name will change to
“alk-#-yn-#-suffix. (See #6 above.)
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Functional Group
1. Carboxylic acid
R
2. Anhydride
O
C
R
3. Ester
R
4. Acid halide
R
R
6. Nitrile
OH
not considered
alkanoic acid
O
C
not considered
alkanoic anhydride
(if symmetrical)
#-alkoxycarbonyl
alkyl alkanoate
(R') (RCO2)
Cl
#-chlorocarbonyl
alkanoyl chloride
NH2
#-carbamoyl
(or #-amido)
alkanamide
#-cyano
alkanenitrile
#-oxo
alkanal
O
C
O
O
C
O
O
C
O
C
5. Amide
prefix
suffix
R
R'
R C N
7. Aldehyde
8. Ketone
R
R
O
C
O
C
H
R'
#-oxo (older = #-keto)
#-alkanone
9. Alcohol
R OH
#-hydroxy
#-alkanol
10. Thiol
R SH
#-mercapto
(or #-sulfanyl)
#-alkanethiol
11. Amine
R NH2
#-amino
#-alkylamine
#-alkanamine
12. Ether
R O R'
12. Sulf ide
R S R'
#-alkoxy (if more than 5C's, then #-alkyloxy)
(can also use "#-oxa" pref ix and
count as carbon in longest chain)
#-alkylthio
12. Halogen
R X
#-fluoro, #-chloro, #-bromo, #-iodo
12. Azide*
R N3
#-azido
12. Diazo*
R N2
#-diazo
12. Nitro*
R NO2
#-nitro
12. Nitroso
R NO
#-nitroso
12. Carbon branches
R
The part of each name
specif ic to the f unctional
group is in bold and
underlined to help you
see those f eatures. They
are not part of the names.
"R" = carbon chains
alkane
alkyl
#
chain
branch
carbons name
name
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
methane
ethane
propane
butane
pentane
hexane
heptane
octane
nonane
decane
undecane
dodecane
tridecane
tetradecane
pentadecane
hexadecane
heptadecane
octadecane
nonadecane
always pref ixes (no suf f ix names)
proper order is alphbetical
#-alkyl, #-(alk-#-enyl), #-(alk-#-ynyl)
* = f ormal charge is necessary in these Lewis structures and there are two reasonable resonance structures
stereoisomerism pref ixes parent stem C/C pi bonds high priority suf f ix
R/S and E/Z
branches and see box
above
low priority
f unctional groups
methyl
ethyl
propyl
butyl
pentyl
hexyl
heptyl
octyl
nonyl
decyl
undecyl
dodecyl
tridecyl
tetradecyl
pentadecyl
hexadecyl
heptadecyl
octadecyl
nonadecyl
-ene
-yne
see list
above
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Practice problems
alkanes, alkenes, alkyne, alka-#,#-dienes alka-#,#-diynes, alk-#-en-#-yne
Problems
a
g
b
h
c
i
d
e
j
f
Answers
a
g
octane
oct-6E-en-1-yne
b
oct-1-ene
h
c
3-methyloct-1-en-7-yne
octa-1,5E-diene
i
d
octa-1,6Z-diene
3-methyloct-7-en-1-yne
e
oct-1-yne
f
j
nona-3E,5Z-dien-1,8-diyne
oct-1-en-7-yne
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Functional group examples (high priority group gets suffix, all others named as prefixes)
f unctional group:
suf f ix:
pref ix:
O
O
O
OH
name:
O
name:
O
5
f unctional group: amide (1o, 2o, 3o)
suf f ix: -amide
pref ix: amido or carbamoyl
O
O
NH2
5
4
3
2
1
OH
name: butanoyl chloride
O
O
NH2
name: 2-amidopent-4-ynoic acid
N
name: N-ethyl-N-methylbutanoyl chloride
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f unctional group:
suf f ix:
pref ix:
O
O
H
OH
H
name:
O
O
name:
H
7
8
9
Miscellaneous nitrogen f unctional groups (all have f ormal charge, all named with pref ixes)
O
O
RNO2 =
NO2
N
N
N
=
N2
N3
N
N
N
name:
R-N3 =
RN2 =
10
Complicated structure with most of the functional groups of first year organic chemistry.
O
O
O
O
O
Cl
NH2
O
O
S
O
H
SH
C
NH2
OH
Br
O
N
O
H
O
6
5
7
4
5
3
6
4
2
1
2
1
1
2
4
2
O
1
O
2
O
5
6
3
4
7
2
O
O
1
4
3
3
O
3
5
Cl
8
NH2
O
1
2
1
3
3
8
9
H
14
12
7
6
5
4
2
S
1
O
1
2
10
13
11
O
H
SH
C
OH
N
O
NH2
3
5
4
9
7
6
8
O
10
Br
This complicated branch (on the
ester oxygen) is named first.
Not in alphbetical order, named in order encountered along the chains.
1-(4-ethylheptyl)-2-amino-3-amido-4-phenyl-6-oxo-7-(4-chlorocarbonyl-5-methoxycarbnoyl-7-pentylcycloocta-5E,7Z-dienyl)-8-bromo-10-ethylthiodeca-3E,7Z-dienyl 2-benzyl-4-hydroxy-5-(2-methylpropoxy)-6-cyano-7-(3-hexyl-4,4-dimethylcyclobut-2-enyl)-9,14-dioxo-12-f ormyltetradec-5E-en-10-ynoate
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Problem - Identify each of the substituent patterns below by its common name. Point out an example of a 1 , 2o,
3o and 4o carbon and nitrogen in the side chains. Also, point out an example of a methyl, methylene and methine
(methylidene) position.
o