Chemistry 122
Homework Ch9 Key
13, 14, 18, 22, 26, 28, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 64, 66, 69.
17.13
B, C, D, F
9-14
(a)
Cortisone contains three ketones, one 3° alcohol, one 1° alcohol, and one carboncarbon double bond. Aldosterone contains two ketones, one aldehyde, one 1°
alcohol, one 2° alcohol, and one carbon-carbon double bond.
(b) The stereocenters are identified with asterisks.
CH2OH
CH2OH
O
H3C C O
CH C O
HO
O
OH


 
H3C  H 
H3C  H 

H


H
O
26

H
O
Cortisone
= 64 possible stereoisomers
27
Aldosterone
= 128 possible stereoisomers
9-18
The following are structural formulas for each ketone.
O
O
(a)
(b)
Cl
O
(d)
9-22
(a)
H
(c)
O
O
(e)
O
(f)
When a carbonyl is in between two other carbons, the compound is a ketone, not
an aldehyde. Ketones have an –one ending and aldehydes have an –al
ending. The correct name is 2-pentanone.
O
3
2-pentanone
1
5
2
4
(b) The name cyclopentanal implies that the carbonyl is on a ring carbon. If this
is the case, the correct name should be cyclopentanone because the
compound must then be a ketone, not an aldehyde.
O
cyclopentanone
(c) The longest continuous carbon chain was incorrectly identified. The correct
name is 3-methyl-2-pentanone.
O
1
O
3
3-methyl-2-pentanone
2
not
1
3
2
4
4
5
H2N
3
(d) The parent chain was numbered incorrectly. The ring carbon bearing the
carbonyl substituent is carbon #1, and then the ring carbons are numbered in
the direction giving the carbon bearing next substituent (an amino group) the
next lowest possible number. The correct name is 3-aminobenzaldehyde.
O
O
6
2
H2N
H
H
5
1
1
not
4
6
5
4
2
3
9-26
Acetone has the higher boiling point than ethyl methyl ether because the intermolecular
dipole-dipole attractive forces between the carbonyl groups of acetone molecules is
greater than the dipole-dipole attraction between ethyl methyl ether molecules.
9-28
Acetaldehyde is a hydrogen bond acceptor and forms hydrogen bonds with water
primarily through its carbonyl oxygen.
O H
H
H
 C O 
H3C
H 
O H
9-36
The reduction of a carbonyl involves adding H2 to the C=O bond.
one non hydrogen group attached
to the C-OH carbon
O H
H
O
2
H
R1
R1 C
transition metal
aldeyhde
H
added hydrogen
H
1o alcohol
two non-hydrogen groups attached
to the C-OH carbon
O
R2
R1
ketone
H2
transition metal
O
H
R1 C
H
added hydrogen
R2
2o alcohol
R1, R2: alkyl, vinyl, or aryl
9-38
Reduction of an aldehyde or ketone by NaBH4 gives the same products as reduction by
H2 in the presence of a transition metal catalyst such as palladium. Under these
reducing conditions, an aldehyde gives a 1° alcohol and a ketone gives a 2°
alcohol.
OH
(a) CH3CHCH2CH3 (b) CH3(CH2)4CH2OH
OH
(c)
CH2OH
CH3
(d)
OH
9-40
The first two reactions are reductions, the second two are oxidations.
O
(a,b) CH3CH2CH2CH2OH
(c,d) CH3CH2CH2COH
9-42
(a) and (b): True
no false statements
9-44
Compound (a) has one enol. Compounds (b) and (c) have two enols each.
OH
OH
(b) CH3C=CHCH3 and CH2=CCH2CH3
OH
and
CH3
OH
(a) CH3CH=CH
OH
(c)
CH3
9-46
(a)
The functional groups of warfarin are circled and identified.
(b) The enantiomer of (S)-warfarin is drawn as its mirror image.
carbonyl
O
O
hydroxyl
OH
O
OH
O
O
ester
(S)-Warfarin
(c) The reduction of
O
(R)-Warfarin
O
OH
O
O
O
O
O
(S)-Warfarin (enol form)
O
(S)-Warfarin (keto form)
(d) The reduction of (S)-warfarin creates a new chiral center. The resulting
product is a mixture of diastereomers.
OH
OH
*
O
OH
O
O
NaBH4
O
O
OH
OH
O
(e)
*
O
 1 g warf   1 mol warf
4 mg warf 

 1000 mg warf   308.3 g warf
9-48
(a)
acetal (b)
(d) cyclic acetal
  6.02 x 10 23 molec 
= 8 x 1018 molec



  1 mol warf
hemiacetal
(e) cyclic acetal
(c) acetal
(f) neither
9-50
Following are equations for the formation of each hemiacetal and acetal.
O
CH3OH
(a) CH3CH2C-H
H+
(b)
O
OH
CH3OH
CH3CH2C-H
H+
OCH3
OH
CH3OH
H+
OCH3
OCH3
CH3CH2C-H + H2O
OCH3
CH3OH
OCH3
H+
OCH3
+ H2O
9-52
The combination of 1-phenyl-1,2-ethanediol and formaldehyde forms a cyclic acetal.
OH
H
+ O C
H
OH
H+
O
+ H2O
O
cyclic acetal
9-54
Hydration refers to the addition of one or more molecules of water to a substance. An
example of hydration is the acid-catalyzed addition of water to propene to give 2propanol. Hydrolysis refers to the reaction of a substance with water, generally with the
breaking (lysis) of one or more bonds in the substance. An example of hydrolysis is the
acid-catalyzed reaction of an acetal with a molecule of water to give an aldehyde or
ketone and two molecules of alcohol. Another example of hydrolysis is the reverse of
Fischer esterification (Chapter 18), namely the hydrolysis of an ester to give a carboxylic
acid and an alcohol.
9-56
The flow chart shows the synthesis of each target molecule.
Br
HBr
O
OH H SO
2
4
H2/Ni
Br
Br2
heat
or
1. NaBH4
2. H2O
Br
H2/Ni
9-58
Compounds (a), (b), and (d) can be formed by reduction of the aldehyde or ketone shown.
Compound (c) is a 3° alcohol and cannot be formed in this manner.
O
O
O
O
H
(a)
(b)
(d) H
H
9-64
Using this reducing agent, each aldehyde is converted to a 1° alcohol and each ketone is
converted to a 2° alcohol.
OH
OH
(a) HOCH2CH2CH2CH2CHCH3
CH2OH
OH
CHCH2CH3
OH
(d)
(b)
(e)
9-66
Following is a structural formula for each compound.
OH
O
O
(a) CH2CCH3
(b) CH3CHCH2CH
Cl
CH3 O
O
O
(d)
(e)
CCH2CH
CH3
OH
(c) HOCH2CHCH2OH
CH3O
(f) HO
CH2OH
O
OH
(c) CH3CCH2CCH3
CH3
OH
O
(f)
9-69
a) Benzaldehyde will react with Tollens reagent to produce a silver mirror.
b) Benzaldehyde will react with Tollens reagent to produce a silver mirror.
H