Phenols,
andThiols
7 " Alcohols,
Chapter
Nomenclature and Structure of Alcohols
7.26 Name eachof the following alcohois:
a. cHrcHrcH(oH)cH2cH3
b. (CH3)2CHCH(OH)CH2CH3
c. CHrCH(Cl)CH(OH)CHrCH3 d. CH3CH(CI)CHTCH(OH)CH3
7.27 Write a structural formula for each of the following compounds:
a.
d.
g.
j.
2,2-dimethyl-1-butanol
2-phenylethanol
cis^2-meth1'lcyclopentanol
2-cyclohexenol
b. p-bromophenol
€. sodium ethoxide
h. (S)-2-butanethiol
c. 2,3-pentanediol
f. l-methylryclopentanol
i. 2-methyl-2-propen1-ol
7.28 Name each of the follorving compounds:
a. CHrC(CH3)rCH(OH)CH3
b. CH3CHBTC(CH3)2OH
.
CH.
d.l><
"oH
OH
I
a/:o'-ut
t.n
"'ll\z i
,,OH
CH,
g. CH3CH:CHCHTOH
i. HOCHTCH(OH)CH(OH)CHTOH
j.
(CH3)2CHO-K"
7.29 Erplain rvhy eachorthe follorving namesis unsatisfactor,v,
and give a correct name:
a. 2-ethyl-I -propanol
C. 1-propene-3-ol
e. 3,6-dibromophenol
b. 2,2-dimethyl-3-butanol
d. 2-chloro-4-pentanol
7.30 Thymolis an antibacteria.l
oil obtainedfrom thyme (Tl.tymus
vulgaris).
TheIUPACnameof thiscompoundis 2-isopropyl-5-meth,vlphenol.
Draw
the structureof th1nnol.
Thyme (Ihymus vulgaris),
sourceof the antibacterial
oil thymol.
PropertiesofAlcohols
7.31 Classifi'the aicoholsin parts a, d, f, g, i, and j of Problem 7.27as primary, secondarl,,
or terriary.
7.32
Lrranee the compounds in each of the follou'ing groups in order of increasingsolubiliw in water, and briefly
explain vour ans\^/ers:
a. ethanoi;ethr4chioride;i-he;lanoj
; ,5-pentanedio
b. i-pentanol1
I IlO
; CH:(CHOH)3CH.OH
Acid-Base Reactionsof Alcohols and Thiols
7.33 The following classesof organic compounds are Lewis bases.Write an equation that showshow each class
m i g h t r e a c tr , r ' i t hI l - .
a. ether,RijR
7 .34
b. amine,R3N:
c. ketone,R2C:(i
Lrraneethe following compoundsin order of increasingacidity,and explain the reasonsfor your choiceof order:
ryclohexanol,phenol,p- nitrophenol,2 -chlorocyclohexanol.
7.35 Which is the strongerbase,potassiumr-butoxideor potassiumethoxide?(Hint: tJsethe data in Table 7.2.)
7.36 Completeeachof the following equarions;
a. cH3cH(oH)cHrCH3 + K *
c. Cl<
b. (cH3)2cHoH + NaH -
i-\
)\-oH + NaoH\.:,/
-1
.H
d. i X 'ou + NaoHc-_/
e. CH3CH:CHCHTSH + NaOH +
7'37 Explain why your answersto parts c, d, and e of Problem 7.36 areconsistentwith the pK,'s of the starting acids
a n d p r o d u c ta c i d s( s e ee q s . 7 . 1 4 , 7 . 1 5a,n d 7 . 4 8 ) .
Acid-Catallzed Dehydration of Alcohols
7.38 Show the structures of aii possible acid-catalyzeddehydration products of the following. If more than one alkene
is possibie,predict which one will be formed in the largest amount.
a. cyclopentanol
c. 2-butanol
b. t-methylcyclopentanol
d. 2-phenylethanol
7.39 Erplain why the reactionshowr i:r eq. 7.19occursmuch more easilythan the reaction
(CH3)3C-OH s -r (CH3)3C* + HO-. (That is, why is it necessary
to protonatethe alcoholbefore ionization
can occur?)
7.40 Draw a reactionenergydiagram for the dehydrationof tert-butylalcohol (eq.7.21).Includethe stepsshown rn
eqs.7.18-7.20 in your diagram.
7.41 \Vrite out all the stepsin the mechanism for eg.7.24,showing how each product is formed.
Alkyl Halides from Alcohols
7.42 Although the reaction_shownn eq.7.26occurs fasterthan that shown in eq.7.28, the yield of product is lower.The
yield of r-butyl chloride is only 800/0,whereasthe yield of n-buryl chloride is nearly t0o%. What by-product is
formed in eq.7 .26,and by what mechanism is it formed? \44'rfis a similar by-product not formed tn eq.7.28?
7.43 Tteatment of 3-buten-2-ol with concentratedhydrochloric acid gives a mixture of two products, 3-chioro-lbuteneand l-chloro-2-butene.Write a reactionmechanismthat explainshow both productsare formed.
Synthesisand Reactions of Alcohols
7.44 Write an equation for eachof the following reactions:
a.
d.
g.
j.
2-methyl-2-butanol
+ HCI
2-phenylethanol
+ SOCI?
l - o c t a n o l+ H B r - t Z n B r 2
2 cycloherylethanol
+ PCC
b. 3-pentanol+ Na
e. l-methylcyclopentanol
* H2SO.,heat
h . l - p e n t a n o l* a q u e o u s N a O H
c. cyclohexanol+ pg1,
f. ethyleneglycol + HONO2
i . l - p e n t a n o l- F C r O 3 , H *
7.45 Write an equation for eachof the following two-stepsprtheses:
a' cyclohexene
to cyclohexanone b. 1-chlorobutane
to butanal
c. 1-butanolto i-butanethioi
Oxidation Reactionsof Alcohols, Phenols, and Thiols
7.46 The alcoholcitronellol is a terpenefound in roseoil. The product
formed when citronellol is oxidized with pyridinium chlorochromate
(PCC) is a constituentof lemon oil. Draw the structureof the product
when citronellol is oxidized with PCC.
:iilc,neiioi
7.47 What product do you expect from the oxidation of cholesterolwith CrO3 and H*? (Seep. 223 for the formula of
cholesterol.)
7.48 Draw the structure of the quinone expectedfrom the oxidation of
OH
a. Z*
I
=-^Y
I
ll
I
Z-"y/oH
b'l
r-TJ
ll
\---oH
OH
7.49 Dimethyl disulfide, CH3S-SCH3, found in the vaginal secretionsof female hamsters,acts as a sexualattractant
for the male hamster.Write an equation for its simthesisfrom methanerhiol.
7.50 The disulfideshorvnbelorn'is
a componentof the odoroussecretion
of mink. Describea sl.nthesis
of this disuifide,startingr.r,ith3-meth)41-butanol.
(TMNQ) is a quinone that rr.asrecentlyisolatedfi'om tobaccoleavesand
7.51 2,3,6-Trimethyl-1,4-naphthoquinone
was shown to slou'the metaboiismof dopamine,a neurotransmitteru'hosedepletioncan lead to Parkinson'sdisease.\\hat is the structure of the hydroquinone rl'hose oxidation givesTMNQ?
-rMMQ