3.E: Organic Nomenclature (Exercises)

Exercise 3-1 Draw structural formulas corresponding to the following names:

a. 2,7,8-trimethyldecane
b. 2,3,4-trimethyl-4-propylheptane
c. 5-(1,1-dimethylpropyl)nonane
d. 4-(chloromethyl)-5-(1-nitroethyl)decane

Exercise 3-2 Give the IUPAC name for each of the following structures:

a. \(\ce{(CH_3)_2CHCH(CH_3)CH_2CH(CH_3)_2}\)
b. \(\ce{CH_3CH_2CH_2CH(CH_3)CH(CH_2CH_3)CH_2CH_2CH_3}\)
c. \(\ce{CH_3CH_2CH(CH_2CH_2CH_3)CH_2CH(CH_3)_2}\)
d. \(\ce{CH_3CH(CH_3)CH(CH_3)CH(CH_3)CH(CH_3)_2}\)

Exercise 3-3 The following are improper IUPAC names. Determine what is incorrect or ambiguous about the name and give the correct name.

a. 2-methyl-3-propylpentane
b. 3-methyl-3-chloropentane
c. 2,3,3,7,7-pentamethyloctane
d. 3-(1,1-dimethylethyl)pentane

Exercise 3-4 Write structural formulas for each of the following:

a. (2,2-dimethylpropyl)cyclopentane
b. 1,2,3-tri(chloromethyl)cyclopropane
c. 1,4-dicyclohexylcyclooctane
d. 1-(1-methylcyclopropyl)-1,2,2,3,3-pentamethylcyclopropane

Exercise 3-5 Give the IUPAC name for each of the following:

a.

b.

c.

d.

Exercise 3-6 Write structural formulas corresponding to the following IUPAC names:

a. 1,3,6-trimethylcyclohexene
b. 1,2,3,3-tetrachlorocyclopropene
c. 2,5-dimethyl-1,5-hexadiene
d. 3-methylidenecyclohexane

Exercise 3-7 Give the IUPAC name for each of the following:

a.

b.

c.

d.

Exercise 3-8 Draw structures for the following compounds:

a. 1,3-hexadien-5-yne
b. 1-cyclodecen-4-yne
c. 5-ethynyl-1,3,6-heptatriene
d. 3-methylidenecyclooctyne

Exercise 3-9 There are nine heptane isomers of formula \(\ce{C_7H_{16}}\). Write structural formulas for each. Name each by the IUPAC system. (In working a problem such as this, proceed systematically by constructing first the heptane, then all the possible hexanes, the pentanes, and so on. Should you inadvertently duplicate a structure, this will become apparent when you name it; duplicate names usually are easier to spot than duplicate structures.)

Exercise 3-10 Write structural formulas for the eight position isomers of \(\ce{C_5H_{11}Cl}\). Name each as a chloroalkane.

Exercise 3-11 Name each of the following hydrocarbons by the IUPAC system:

a.

b.

c.

d.

e. \(\ce{(CH_3-CH_2-CH_2-)_4-C}\)

f.

Exercise 3-12 Draw the structure of 1,1-dimethyl-3-(1-methyethyl)cyclohexane four times. In the first structure circle all the primary carbons; in the second, circle all the secondary carbons; in the third, circle the tertiary carbons; in the fourth, circle the quaternary carbons.

Exercise 3-13 Draw the possible primary alkyl or alkenyl groups of formulas:

a. \(\ce{C_5H_{11}}\) (four)
b. \(\ce{C_5H_9}\) (eight)

Exercise 3-14 Write structural formulas for the following substituent groups:

a. chloromethyl
b. 1-chloroethyl
c. 3-methylbutyl
d. 1,2-dimethylpropyl
e. 1-methyl-2-propenyl
f. 2-methyl-1-propenyl
g. 1-buten-3-ynyl
h. 2-methylcyclohexyl
i. 2-cyclohexenyl
j. phenylmethyl
k. para-nitrophenyl
l. 2,4-dichlorophenyl
m. propylidene

Exercise 3-15 Name the following substituent groups by the IUPAC system and indicate whether they are primary, secondary, tertiary, or aryl groups:

a. \(\ce{BrCH_2CH_2CH_2}-\)
b. \(\ce{(CH_3CH_2)_3C}-\)
c. \(\ce{CH_3C \equiv CCH_2}-\)

d.

e.

f.

g.

Exercise 3-16 Write structural formulas for each of the following substances:

a. 1-octene
b. 1,4-hexadiene
c. 1,2-dimethylcyclobutane
d. 1,2-cyclononadiene
e. 3-chloro-3-methyl-1-butyne
f. cyclooctyne
g. 2-chloro-1,3-butadiene
h. 3-methyl-2-hexen-4-yne
i. (1,1-dimethylethyl)benzene
j. (1-methylpropyl)benzene
k. meta-nitrotoluene
l. 1-phenyl-1-methylcyclohexane
m. (phenylmethyl)cyclohexane

Exercise 3-17 Name each of the following substances by the IUPAC system:

a. \(\ce{(CH_3)_2C=CHCH_3}\)
b. \(\ce{Cl_2C=C(CH_3)_2}\)
c. \(\ce{(CH_3)_2C=C=CHBr}\)
d.

e.

f.

g.

h.

i.

j.

Exercise 3-18 Decide whether the following structures are named correctly according to the IUPAC rules. If a name is incorrect or ambiguous, assign the correct name:

a. 1-ethyl-2-methylbutane

b. \(\ce{Cl_2CHCHCl_2}\) tetrachloroethane

c. 1-methyl-2-cyclohexene

d. \(\ce{CH_2=CHCH_2Cl}\) 1-chloro-2-propene

e. 2-ethynyl-2-butene

f. phenylpropane

g. dinitrobenzene

h. \(\ce{(CH_3)_2CHCH_2CH_3}\) isopentane

Exercise 3-19

a. The major component in the oil obtained from pressing the rinds of oranges and lemons is a hydrocarbon called limonene. It is obtained in commercial quantities from citrus rind and is sold as a flavoring and perfume agent. Name limonene by the IUPAC system.

b. The carbon skeleton of limonene is made up of branched five-carbon repeating segments called isoprene (or isoprenoid) units. Furthermore, limonene has the formula \(\ce{C_{10}H_{16}}\), which corresponds to two \(\ce{C_5H_8}\) isoprene molecules linked together.

What is the IUPAC name for isoprene? Indicate the isoprene units in the limonene structure by drawing a dotted line through each of the bonds that joins one isoprene unit to the other.

c. Like limonene, \(\beta\)-carotene and vitamin A have carbon skeletons made up of isoprenoid units. These compounds belong to a class of naturally occurring compounds called terpenes. Mark off the isoprenoid units in \(\beta\)-carotene and vitamin A as you did for limonene.

Exercise 3-20 If you have access to the 1967-71 Eighth Collective Subject Index of Chemical Abstracts, locate the page number in the index where each of the compounds shown in Exercise 2-8 occurs and give the name used. Notice that past Chemical Abstracts indexes do not use completely systematic nomenclature, especially for compounds with only a few carbons, but these indexes will be made completely systematic in the future.

Contributors

John D. Robert and Marjorie C. Caserio (1977) Basic Principles of Organic Chemistry, second edition. W. A. Benjamin, Inc. , Menlo Park, CA. ISBN 0-8053-8329-8. This content is copyrighted under the following conditions, "You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format."