Jim Hollister/Rolf Unterleitner
SASC/UC Davis
Naming Cycloalkanes: Nomenclature Examples
KEY
Name the following molecules.
1)
HO
F
NO2
Name: 4-fluoro-3-nitrocyclohexanol. (Since the alcohol has highest precedence, its carbon is
given the lowest number. Precedence of groups are listed on nomenclature handout on workshop
website.)
2)
HO
F
CH2CH3
Name: 3-ethyl-4-fluorocyclohexanol
3)
Cl
Name: 1-(3-chloro-4-ethylcyclopentyl)-5-methylhexane, not 1-chloro-2-ethyl-4-(5methylhexyl)-cyclopentane
4)
Name: 3-ethyl-1,1-dimethylcyclohexane Uses lowest numbers: 1,1,3 is lower than 1,3,3. (The
second substituent, one of the methyls!, would have the lower number of 1 in the correct answer;
in the incorrect answer, 1-ethyl-3,3-dimethylcyclohexane, the second substituents (the methyls)
would each have a 3.)
5)
Name: 1-ethyl-3-methylcyclohexane Uses alphabetical rule to determine C-1.
6)
Cl
Name: 1-chloro-2-(2-methylpentyl)-cyclopentane When there is a tie in the number of
carbons between a cyclic alkane and a regular alkane, choose the cycloalkane as the parent chain.
7)
Name: cis-1-(1-methylethyl)-3-propylcycloheptane
or
cis -1-isopropyl-3-propylcycloheptane
8)
Br
Name: 4-bromo-1-ethyl-2-methylcyclopentane
Warning: Stereochemical information on the substituents is not indicated in the
answer. This requires knowledge from chapter 5. ( You can't use cis and
trans because there are three groups on the ring; R and S would be used.)
9)
F
Name: trans-4-(2,2-dimethylpropyl)-3-fluoro-1,1-dimethylcycloheptane
or trans-3-fluoro-1,1-dimethyl-4-neopentylcycloheptane
Even though there are more than two substituents on the ring, you can use trans because
the methyl groups are on the same carbon and they do not confuse the meaning of using cis or
trans.