Organic Exam Review – Solutions
Question 1
a)
Br2
substitution
ethane
bromoethane
b)
Cl2
addition
propene
1,2 - dichloropropane
c)
substitution
HI
I2
Benzene
Iodobenzene
d)
OH-
H2O
chloropropane
Cl_
reduction
elimination
propene
e)
esterfication
H2O
butanoic acid
methyl butanoate
methanol
f)
H2O
ethanol
dehydration
elimination
ethene
g)
O2
methylbenzene
CO2
H2O
combustion
strong oxidation
h)
O
O
oxidizer
oxidizer
ethanol
ethanal
oxidation
ethanoic acid
i)
H2O
methanol
ethanol
dehydration
methoxyethane
j)
NH3
H2O
pentanamide
pentanoic acid
k)
substitution
H2
methane
methanamine
l)
O
H2
oxidizer
oxidation
propanone
propan-2-ol
Question 2
a) The reaction between benzene and 2 moles of chlorine gas.
Cl
+ 2 Cl
benzene
AlCl 3
Cl
+2H
Cl
meta-dichlorobenzene
1,3-dichlorobenzene
Substitution Reaction
b) The formation of hexan-2-ol from an alkene.
Cl
elimination
dehydration
+
H2SO 4
H2O
OH
100 C
1-hexene
2-hexanol
hexan-2-ol
hex-1-ene
Addition Reaction
c) The formation of pentane-2,2-diol.
OH
+
H2SO4
2 H2O
1-pentyne
pent-1-yne
100 C
OH
2,2-pentanediol
pentane-2,2-diol
Addition Reaction
d) The oxidation of hexan-3-ol with potassium dichromate.
K 2Cr 2O 7
+ H2O
O
OH
3-hexanone
hexan-3-one
3-hexanol
hexan-3-ol
dichromate changes from orange to green
Oxidation Reaction
e) The reduction of butanal.
Pt
+
O
H2
butanal
101 MPa
OH
1-butanol
butan-1-ol
Reduction Reaction (Addition Reaction)
f)
The reaction between trans-hex-2-ene with hydrogen bromide (to make two positional isomers).
Br
+
trans-2-hexene
trans-hex-2-ene
+
HBr
hydrogen bromide
2-bromohexane
Br
3-bromohexane
Addition Reaction
g) The formation of ethyl benzoate.
O
O
OH
benzoic acid
+
H2SO4
OH
heat
ethanol
Condensation Reaction
h) The formation of butan-2-ol.
O
ethyl benzoate
+
H2O
+
OH
H2SO4
H2O
100 °C
2-butanol
butan-2-ol
1-butene
but-1-ene
Addition Reaction
-could also use 2-butene
but-2-ene
i)
The reaction that would occur if ethyl propanoate was heated in the presence of water and acid.
O
O
H2SO4
+ H2O
O
ethyl propanoate
j)
OH
heat
+
ethanol
HO
propanoic acid
The reaction between 2 moles of water with pent-2-yne.
OH
OH
H2SO4
+2
H2O
1-pentyne
pent-2-yne
100 C
OH
2,2-pentanediol
+
OH
3,3-pentanediol
pentane-2,2-diol
pentane-3,3-diol
Addition Reaction
k) The oxidation of butan-2-ol.
O
KMnO4
OH
+
H2O
butanone
2-butanol
butan-2-ol
- KMnO4 changes from purple to brown
- K2Cr2O7 will change from orange to green
Oxidation Reaction
l)
The oxidation of butan-1-ol.
KMnO4
OH
1-butanol
butan-1-ol
O
+
O
KMnO4
H2O
HO
butanoic acid
butanal
- KMnO4 changes from purple to brown (K2Cr2O7 will change from orange to green)
Oxidation Reaction
m)
Show the formation of but-2-ene from an alcohol.
OH
H SO
2
2-butanol
butan-2-ol
4
100 °C
2-butene
but-2-ene
Elimination Reaction
- also produce 1-butene
but-1-ene
+
H2O
+
2 H+
n) Show the reaction between methanol and butanoic acid.
OH
H2SO4
2-butanol
butan-2-ol
100 °C
+
H2O
2-butene
but-2-ene
Elimination Reaction
but-1-ene
- also produce 1-butene
o) Show the reaction between water and cyclohexene.
OH
H2SO4
+
H2O
100 °C
Addition Reaction
p) Show the oxidation of 2-methylbutan-2-ol
O
No Reaction