CHEM1611 Answers to Problem Sheet 7
1.
(CH2)4COOH
(a)
S
(CH2)4COOH
Zn / HCl
SH HS
S
(CH2)4COOH
(b)
(CH2)4COOH
I2 or O2/FeCl3
S
SH HS
2.
NAD+:
S
NADH:
R
R
N
N
NH2
NH2
O
O
(R = adenine dinucleotide)
3.
B
C
D
4.
(a)
OCH2CH3
OCH2CH3
1,1-diethoxycyclopentane
cyclopentene
dilute H2SO4 / heat
OH
cyclopentanol
Cr2O7 / H+
CH2CH3OH / H+
O
cyclopentanone
(b)
OH
OH
butan-1-ol
butan-2-ol
conc. H2SO4
(dehydration)
dilute H2SO4 / heat
(Markovnikov addition of H2O)
but-1-ene
(c)
N
OH
ethanol
tetraethylammonium
PBr3
(CH3CH2)3N
[triethylamine]
Br
bromoethane
5.
+
Cr2O72 / H
HO
OH
O
isobutyric acid
2-methylpropan-1-ol
1° alcohol  carboxylic acid
+
OH
butan-2-ol
2° alcohol  ketone
Cr2O72 / H
O
butan-2-one
+
Cr2O72 / H
No reaction
OH
2-methylpropan-2-ol
3° alcohol – no reaction with oxidizing agent
+
H2SO4
OH
2-methylpropan-2-ol
2-methylprop-1-ene
Dehydration of 3° alcohol
+
2-methylprop-1-ene
Hydration of a C=C bond
H2SO4
OH
2-methylpropan-2-ol