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10.7 Alkene & Alkyne Problems

10.7 Extra Problems

11. Determine the degrees of unsaturation for each of the following formulas. Then, draw two possible structures for each formula. a) C5H8O

b) C4H9N

c) C6H10

d) C5H5Cl

e) C4H8

12. Label the following compounds as E, Z, or neither.

Problem 12, alkenes & alkynes problems

13. Name the following compounds. Do not forget cis-, trans-, E-, or Z- when appropriate.

Problem 13, alkenes & alkynes problems

14. Draw the following compounds. a) 4-phenyl-1-butene b) 3-heptyne c) acetylene d) polyethylene e) (E)-4- methyl-2-pentene f) 2-phenyl-1,3-cyclopentadiene g) ethylene h) polypropylene i) (3E, 5Z)-2-methyl-3,5-nonadiene j) cis-3,4-dibromo-3-hexene k) (2E,4E)-octadien-6-yne l) methylacetylene m) cyclohepta-1,3-diene n) cis-3,4-dimethyl-1-cyclopentene o) 2,4-dimethylcyclopentadiene p) 1-cyclohexyl-1,3,5-cycloheptatriene

15. Compounds don’t necessarily need a double bond to have E and Z, you just need geometric isomers (like if they contain rings). Label the following as E or Z.

Problem 15, alkenes & alkynes problems

16. Components of the sex pheromone of the leopard moth have been synthesized. They are A and B, shown below.

Problem 16, alkenes & alkynes problems

Complete the names for A and B. A is ( , )-2,13-octadecadienyl acetate. B is ( , )-3,13-ocdecadienyl acetate.

17. For the following compounds, identify if they have cis-trans isomerism. If they do, draw all of the cis/trans or E/Z isomers. Label them cis, trans, E, or Z. a) 2-methyl-2-butene b) 2-pentene c) 1,3-pentadiene d) 2,3-dichloro-2-butene e) 1-butene f) 1-chloro-1-fluoropropene g) 1-bromo-1-chloro-2-methylpropene h) 2-bromo-1-chloro-1-iodobutene

18. a) Draw the two elimination products formed in the following reaction and indicate which of the two products would predominate.

Problem 18, alkenes & alkynes problems

b) If KOtBu was used instead of NaOH, which of the two elimination products would predominate?

19. Draw the products of the following reactions.

Problem 19, alkenes & alkynes problems

20. Indicate whether or not the following violate Bredt’s rule.

Problem 20, alkenes & alkynes problems

21. Fill in appropriate reagents that would perform the following reactions. a) 1,2-dibromopentane to pentene b) 1-butene to 1,3-butadiene (2 reactions) c)

Problem 21, alkenes & alkynes problems
d)
Problem 21d, alkenes & alkynes problems

22. Propose a mechanism for the following reactions.

Problem 22, alkenes & alkynes problems

23. The following dehydration does not occur. Explain why.

Problem 23, alkenes & alkynes problems

24. Predict the products of the following reactions. If more than one alkene is formed, identify the one that would be made in the greatest amount.

Problem 24, alkenes & alkynes problems