Organic Chemistry

Problems 107

a. 4-bromo-3-pentanol g. 3,3-dichlorooctane

b. 2,2-dimethyl-4-ethylheptane h. 5-ethyl-2-methylhexane

c. 5-methylcyclohexanol i. 1-bromo-4-pentanol

d. 1,1-dimethyl-2-cyclohexanol j. 3-isopropyloctane

e. 5-(2,2-dimethylethyl)nonane k. 2-methyl-2-isopropylheptane

f. isopentyl bromide l. 2-methyl-N,N-dimethyl-4-hexanamine

49. Which of the following diaxial-substituted cyclohexanes has the highest energy?


50. Give systematic names for all the alkanes with molecular formula that do not have any secondary hydrogens.


51. Draw skeletal structures of the following compounds:
    a. 5-ethyl-2-methyloctane d. propylcyclopentane
    b. 1,3-dimethylcyclohexane e. 2-methyl-4-(1-methylethyl)octane
    c. 2,3,3,4-tetramethylheptane f. 2,6-dimethyl-4-(2-methylpropyl)decane


52. For rotation about the bond of 2-methylhexane:
    a. Draw the Newman projection of the most stable conformer.
    b. Draw the Newman projection of the least stable conformer.
    c. About which other carbon–carbon bonds may rotation occur?
    d. How many of the carbon–carbon bonds in the compound have staggered conformers that are all equally stable?


53. Which of the following structures represents a cis isomer?


54. Draw all the isomers that have the molecular formula (Hint:There are eight such isomers.)
    a. Give the systematic name for each of the isomers. d. How many of the isomers are primary alkyl halides?
    b. Give a common name for each isomer that has one. e. How many of the isomers are secondary alkyl halides?
    c. How many isomers do not have common names? f. How many of the isomers are tertiary alkyl halides?


55. Give the systematic name for each of the following compounds:
    a. d. g.

b. e. h.

c. f.

56. Draw the two chair conformers of each compound, and indicate which conformer is more stable:
    a. cis-1-ethyl-3-methylcyclohexane d. trans-1-ethyl-3-methylcyclohexane
    b. trans-1-ethyl-2-isopropylcyclohexane e. cis-1-ethyl-3-isopropylcyclohexane
    c. trans-1-ethyl-2-methylcyclohexane f. cis-1-ethyl-4-isopropylcyclohexane


57. Why are alcohols of lower molecular weight more soluble in water than those of higher molecular weight?


58. The most stable conformer of N-methylpiperidine is shown on p. 108.
    a. Draw the other chair conformer.

OH O

NH 2

Cl

OH

C 5 H 11 Br.

CH 3

CH 3 CH 3

CH 3

CH 3

CH 3 CH 3

CH 3

AB C D

C-3¬C-4

C 7 H 16

AB C

CH 3 CH 3

Cl Cl CH 3 Cl

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