Organic Chemistry

Problems 331

Key Terms

absorption band (p. 322)
1,2-addition (p. 306)
1,4-addition (p. 306)
allene (p. 298)
auxochrome (p. 325)
Beer–Lambert law (p. 324)
blue shift (p. 326)
bridged bicyclic compound (p. 319)
chromophore (p. 322)
concerted reaction (p. 313)
common intermediate (p. 309)
conjugate addition (p. 306)
conjugated double bonds (p. 298)
cumulated double bonds (p. 298)
cycloaddition reaction (p. 313)
cycloaddition reaction (p. 313)
Diels–Alder reaction (p. 313)

[4+2]

diene (p. 298)

dienophile (p. 313)

direct addition (p. 306)

electromagnetic radiation (p. 321)

electronic transition (p. 322)

endo (p. 319)

equilibrium control (p. 310)

excited state (p. 322)

exo (p. 319)

ground state (p. 322)

highest occupied molecular orbital

(HOMO) (p. 314)

isolated double bonds (p. 298)

kinetic control (p. 310)

kinetic product (p. 308)

lowest unoccupied molecular orbital

(LUMO) (p. 314)

molar absorptivity (p. 324)

pericyclic reaction (p. 313)

polyene (p. 298)

proximity effect (p. 311)

red shift (p. 326)

s-cis conformation (p. 318)

s-trans conformation (p. 318)

spectroscopy (p. 321)

tetraene (p. 298)

thermodynamic control (p. 310)

thermodynamic product (p. 308)

triene (p. 298)

ultraviolet light (p. 322)

UV/Vis spectroscopy (p. 322)

visible light (p. 322)

wavelength (p. 322)

Problems

25. Give the systematic name for each of the following compounds:

a. d.

b. e.

c.

26. Draw structures for the following compounds:
    a. (2E,4E)-1-chloro-3-methyl-2,4-hexadiene c. (3Z,5Z)-4,5-dimethyl-3,5-nonadiene
    b. (3Z,5E)-4-methyl-3,5-nonadiene d. (3E,5E)-2,5-dibromo-3,5-octadiene


27. a. How many linear dienes are there with molecular formula (Ignore cis–trans isomers.)
    b. How many of the linear dienes that you found in part a are conjugated dienes?
    c. How many are isolated dienes?


28. Which compound would you expect to have the greater value, 1,2-pentadiene or 1,4-pentadiene?


29. In Chapter 3, you learned that is found in the waxy coating of apple skins. What is its systematic name?


30. Diane O’File treated 1,3-cyclohexadiene with and obtained two products (ignoring stereoisomers). Her lab partner treated
    1,3-cyclohexadiene with HBr and was surprised to find that he obtained only one product (ignoring stereoisomers). Account for
    these results.


31. Give the major product of each of the following reactions. One equivalent of each reagent is used:

a. b. CH 3

+ HBr peroxide

+ HBr

CH 3

Br 2

-farnesene

a-farnesene

-¢H°

C 6 H 10?

CH 3 CH 2 C CCH 2 CH 2 CCH

HOCH 2 CH 2 CH 2 CH 3 CH 3

H H

CC

CH 3 CCHCCH 2 CH 2 CH 2 CH 2 Cl