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3.E: Organic Nomenclature (Exercises)

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  • 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:





    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:





    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:





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


    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. \(\ce{CH_3C \equiv CCH_2}-\)





    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. \(\ce{(CH_3)_2C=C=CHBr}\)







    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.

