Download Systematic Nomenclature of Organic Compounds

Systematic Nomenclature of Organic Compounds
1. Find the longest continuous carbon chain (parent chain).
a. If there is a functional group (double or triple bond, alcohol etc) it must be on or part of the parent chain.
b. If there is a ring in the compound either the ring itself or the non-ringed chain will be the parent chain but
never both combined.
c. If there are two or more chains of equal length, pick the one with the greatest number of substituents.
2. Number the carbons in the parent chain.
a. If there is a functional group, assign it the lowest possible position. If the functional group gets the same
position from either end then consider the lowest number for the substituents. If there is a functional
group on a ring, assign it position 1. Double bonds in a ring are at positions 1 and 2.
b. If there is multiple functional groups the priority is carbonyls > alcohols > carbon-carbon multiple bonds
> amines. If you have a carbon-carbon double bond and a carbon-carbon triple bond, go in the directions
that gives the lowest possible positions. If both directions give the same numbers, the double bond will
take priority.
c. If there are no functional groups, give the substituents the lowest possible numbers. If you get the same
numbers from either end assign the alphabetically first substituent the lowest number.
3. Naming your compound.
a. If the compound has a specific configuration or geometry (cis/trans, E/Z or R/S) indicate this first.
b. The first name is the substituents in alphabetical order. Prefixes that denote a number (di, tri, sec, tert
etc.) are not alphabetized. List the position(s) on the parent chain and denote how many with a Greek
prefix. If a substituent is on a nitrogen the letter N is used to denote the position in lieu of a number.
Hyphens are placed between letters and number whereas commas between two numbers.
c. The last name of the compound is the parent chain. The stem of the name indicates the length of the
parent chain and the suffix reflects the type of compound. If your parent chain is a ring add the prefix
cyclo. If your parent chain had a functional group indicate the position if it’s not obvious.
# of C’s
Stem
1
meth
2
eth
3
prop
4
but
5
pent
6
hex
7
hept
Structure
Classification
Systematic suffix
C–C
alkane
ane
C=C
alkene
ene
C≡C
alkyne
yne
C–X
alkyl halide
N/A
alcohol
anol anediol
enol enediol
ynol ynediol
8
oct
9
non
10
dec
11
undec
Example
pentane
3-hexene
1-butyne
F
2-fluoropentane
C – OH
C–O–C
ether
N/A
OH
cyclopentanol
O
ethoxycyclopentane
C–N
amine
anamine
enamine
ynamine
NH2
2-pentanamine
12
dodec
Substituent Names
cyclopropyl
isopropyl
methyl
hexyl
cyclobutyl
sec-butyl
ethyl
isobutyl
propyl
cyclopentyl
tert-butyl
pentyl
cyclohexyl
butyl
vinyl
fluoro
F
methoxy O
Br
bromo
I
allyl
O
Cl chloro
O
ethoxy
isopropoxy
propoxy
O
phenyl
iodo
benzyl
Common Nomenclature for Organic Compounds
Does your compound have an
element other than C or H?
No – Does your
compound have a
ring or branch?
No – The total
number of carbons
determines the name
of your compound
butane
Yes – Is your hetero
atom bonded to 2 or
more carbon chains?
Yes – The total number
of carbons is the root
name – add the
appropriate prefix
No – Name your
carbon chain followed
by the functional
group name
Br
cyclopentane
tert-butyl bromide
pentane
Yes – Name your carbon
chains in alphabetical
order followed by the
functional group name
O
isopropyl propyl ether
N
isohexane
HO
isobutyl alcohol
ethyldimethylamine