ALKENES PROBLEMS

NOMENCLATURE

  1. Give IUPAC names for the compounds represented by the following structural formulas.

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ALKENES PROBLEMS

a)

b)

c)

d)

e)

f)

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ALKENES PROBLEMS

  1. Draw structural formulas for the following names.

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ALKENES PROBLEMS

a)trans-3-hexene

b)cis-2,3,4,5-tetramethyl-3-hexene

c)ethylene

d)propylene

e)trichloroethylene

f)3-methyl-1-pentene

g)3-isopropylcyclohexene

h)(Z)-1-bromo-1,2-difluoroethene

i)(E)-1-chloro-3-ethyl-4-methyl-3-heptene

j)cis-4-chloro-2-pentene

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ALKENES PROBLEMS

  1. Name the following alkenes

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ALKENES PROBLEMS

a)

b)

c)

d)

e)

f)

g)

h)

i)

j)

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ALKENES PROBLEMS

  1. Draw structures of the following compounds

a)(3Z)-1,3-pentadiene

b)(3E)-1,3-pentadiene

c)(E)-2,5-dibromo-3-ethyl-2-pentene

d)2,3-dimethylcyclohexene

e)3-t-butyl-2-isopropylcyclopentene

f)1-isobutyl-3-sec-butyl-1,4-cycloheptadiene

g)cis-3,4-diethylcyclohexene

h)2,5-dimethyl-1,3-cyclopentadiene

  1. Which is more stable? Draw their structures and circle the more stable compound.

a)1-ethylcyclohexene or 3-ethylcyclohexene

b)(Z)-2-butene or (E)-2-butene

c)2-pentene or 2-methyl-2-butene

  1. State Markovnikov’s rule …………………………………………………………………………………………. ……………………………………………………………………………………………………………………..
  2. Draw and name the structures of the major products of the following reactions.

a)

b)

c)

  1. Draw and name the alkene reagent that would produce the following product.

a)

b)

  1. When treated with KI in H3PO4, vinylcyclohexane produces 1-ethyl-1-iodocyclohexane. Draw the mechanism for the reaction (showing intermediates and products). Note that drawing a mechanism involves pushing electrons using arrows.

  1. Calculate the number of degrees of unsaturation in each of the following
  2. Calculate the number of degrees of unsaturation in each of the following and draw a possible structure.

a)C2HCl3O

b)C3H6O2

c)C4H7NO

  1. Elimination reactions can produce mixed products. This is usually undesirable. Draw and name all the elimination products formed in the following reactions. Identify the major products where possible.
  2. Draw the complete mechanism (including any intermediates) for the addition of I2 (in CCl4 solvent) to cyclopentene and name the product indicating its geometry.

  1. State Zaitzev’s Rule: ………………………………………………………………………………………….. .
  1. When Br2 water is added to 2,3-dimethyl-2-butene, a mixture of vic dihalide and halohydrin form. Draw a mechanism for both reactions. Which one is the major product? Why?
  1. When concentrated H2SO4 is added to cyclohexene, a bisulfate is formed, however, when aqueous H2SO4 is used, an alcohol results. Draw the mechanism for these and give the reason for the difference.
  1. Draw the structure of the normal, ‘Markovnikov’ product formed when H-X (where X is a halogen) is reacted with 1-butene.
  1. When peroxides are present, e.g., H2O2, the antiMarkovnikov product forms, but only with H-Br. Draw a mechanism for this free radical addition reaction with 1-butene. Hint: Br adds first.
  1. Draw the product (showing its stereochemistry) when cyclopentene is oxidized by cold, neutral or alkaline KMnO4.
  1. In the following table, the alkenes in the left column are oxidized by the oxidants shown in the top row. Draw the structures of the products of oxidation in the empty cells.

hot KMnO4 / O3, then Zn in dil. CH3COOH
  1. Draw structures of the main products of the following reactions.

  1. Draw structures or structural formulas of the products of the following reactions. In some cases more than one product may result. Show all the major products

a)

b)

c)

d)

e)

f)

g)

h)

i)

  1. Draw structures of the following:

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ALKENES PROBLEMS

a)methyl group

b)methyl chloride

c)methylene group

d)methylene chloride

e)ethyl group

f)ethyl chloride

g)ethylene group

h)ethylene chloride

i)vinyl group

j)vinyl chloride

k)vinylidene group

l)vinylidene chloride

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ALKENES PROBLEMS

  1. Draw structures of

a)allyl group b) allyl chloride

  1. Name the following compounds including all cis- and trans- isomers where possible.

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ALKENES PROBLEMS

a)CH2=CCl2

b)CH2=CHCl

c)CHCl=CHCl

d)CBrCl=CHCl

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ALKENES PROBLEMS

  1. State the conditions (temp., pressure and catalyst) required to reduce alkenes with H2 gas.
    …………………………………………………………………………………………………………….
  2. Write an equation showing the reduction of 1,3-butadiene with H2 gas. Include catalyst and conditions.
  3. Draw the structure of the alkenes that would produce the following products when treated with O3, followed by dilute aqueous CH3COOH.

a)CH3COCH3+CH(CH3)2CHO

b)CH3CH2CHO only (2 moles of product per mole of reagent)

  1. Three rapid qualitative lab tests are commonly used to identify alkenes. Baeyer’s test (cold, weakly acidic, dilute KMnO4 solution), the Bromine test (2% Br2 in CCl4 or in water), and the Sulfuric Acid test (using concentrated H2SO4). Briefly explain what a positive test would look like and explain why.
  2. Write structural formulas of the major products forming when 1-methylcyclopentene reacts with each of the following reagents. Show stereochemistry where cis- and trans- isomers form.

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ALKENES PROBLEMS

a)HI

b)H2/Pt

c)dilute H2SO4, warm

d)cold, concentrated H2SO4

e)cold, concentrated H2SO4, then H2O & heat.

f)Br2 in CCl4

g)Br2 in H2O

h)cold, dilute KMnO4

i)O3, then Zn in dil. CH3COOH

j)KMnO4, OH-, and heat

k)BH3, then H2O2 and OH- (pH8).

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ALKENES PROBLEMS

  1. List all reagents needed to synthesize the following products from 2-methylpropene (isobutylene).
  2. Outline a synthesis for each of the following products from the starting reagents shown. More than one step may be necessary. List all reagents needed but mechanisms are not required.

a)

b)

c)

d)

e)

f)

g)

  1. Draw and name the products of the following reaction indicating which is major and which is minor.
  2. Draw structures of

a)isobutylene

b)isoprene

  1. Write the products of the following oxidation reactions, then balance the redox equations.

a)

b)

  1. Balance the following half reactions and identify them as being either oxidation or reduction.

a)(in alkaline media)

b)(in neutral media)

c)(in acidic media)MnO4-  Mn+2

d) HNO3  NO2

e) HIO4  HIO3

f) (in alkaline media)H2O2  2O-2

g) Cl2  2Cl-

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