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Year 13 Chemistry Assignment No. 17
Organic #3
Reaction sequences
(63 marks)
1.
COMPOUND A
CH2
CH2
Reaction with H 2O in
Reaction with HCl
presence of a catalyst
COMPOUND B
COMPOUND D
Oxidation with acidified dichromate
which changes from orange to green
Reaction with excess NH 3
COMPOUND C
CH3 CH2 NH2
Compound E can react with
Na2CO3 soln to form CO2
COMPOUND E
and turns blue litmus red
Reaction due to heating the dried
compounds C and E together
COMPOUND F
H
CH3 CH2 N
C
CH3
+
COMPOUND G
O
(a)
Give the name and formulae of all the compounds in the above diagram.
(b)
What is the name of the linkage in compound F?
(c)
Name an important biological compound that contains this linkage.
2.
Complete the following flow sheets: For “F” put the formula, for “N” put the name and for “R” put the formula of the reagent that would
accomplish the transformation.
(a)
1
O
F
CH3CCH3
N
R
Br2
R
CH3CH2CH3
CH3CH=CH2
aq. dil
H2SO4
F
N
(b)
excess
NH3
F
N
CH3CH2CH2Cl
N
Aq NaOH
reflux
R
F
R
R
N
CH3CH2COOH
CH3CH2CCl
O
CH3CH2OH
Conc H 2SO4
R
O
R
CH3CH2CNH2
N
3.
F
A 1-alkene, “A” C5H10 , when treated with HBr gives an alkyl bromide, “B”, C5H11Br, as the main
product. When “B” is reacted with alcoholic KOH solution it gives compound “C”, an isomer of
“A”, as the major product. “C” cannot exhibit cis-trans isomerism. When “B” is reacted with
aqueous NaOH it gives compound “D”, C5H11OH. “D” can be oxidised with acidified potassium
dichromate to give compound “E”. Compound “E” does not react with Tollens, Fehlings or
Benedicts solutions.
Draw the structures of the three possible 1-alkenes and by following through their reactions with
the above reagents deduce the actual structures of “A”,”B”,”C”,”D” and “E” and give the
systematic names of all five of these compounds.
2
4.
heat with
acidified
KMnO4
Compound B
M = 58 g mol -1
Compound A
C3H8O
heat with
50%
H2SO4
heat with ethanoic
acid and H2SO4
catalyst
Compound C
M = 102g mol -1
Compound D
M = 42g mol -1
+ H2(g)
+HBr
Pt
catalyst
Compound F
Compound E
Copy and complete the following table: Systematic
name
Compound M / g mol-1 Structural
formula
A
60
B
58
C
102
D
42
Organic
class
secondary alcohol
isopropyl ethanoate
E
F
5.
alkane
123
CH3 -CHBr -CH3
The following is a chart for a series of organic reactions:
Propan-1-ol
Cr2 O7 2 - / H +
Compound A
Turns blue litmus
pink.
SOCl2 or PCl 3
Compound B
reacts vigorously with
water
CH3 CH2 OH
NH3
Compound C
Sweet - smelling
insoluble in
water
(a)
(b)
Compound D
A white solid, soluble in
water.
No reaction to litmus.
What classification of alcohol is propan-1-ol?
Draw the structural formula of compounds A - D.
3
6.
7.
(a)
Draw the structure of another ester with the same molecular formula as the following ester:
CH3 C O CH2 CH2 C CH3
I
II
CH3
O
What is the systematic name for the following molecule?
CH3 CH2 CH2 C
CH C O O H
CH3
(b)
Draw the geometric isomers of pentene.
8.
(a) Complete the following scheme for the conversion of pent-1-ene to pentan-2-one:
CH3 CH2 CH2 CH
pent-1-ene
CH2
H2 O / H2 SO4
step X
name
reagent
pentan-2-one
(b)
Write the structural formula for the other possible organic product that could result from the
reaction at step X.
4
Answers
Year 13 Chemistry Assignment No. 17
Organic #3
Reaction sequences
(63 marks)
1.(a)
A.
B.
C.
D.
ethene
monochloroethane
Amino ethane
Ethanol
(b)
(c)
Peptide bond
Proteins
CH2CH2
CH2ClCH3
CH3CH2NH2
CH3CH2OH
E.
F.
G.
Ethanoic acid
CH3COOH
Ethyl ethanamide CH3CH2NHCOCH3
Water
H2O
(14)
(1)
(1)
2.(a)
O
F
CH3CHBrCH2Br
N
1,2-dibromopropane
CH3CCH3
R
Br2
H2 / Pt
R
CH3CH2CH3
CH3CH=CH2
aq. dil
H2SO4
F
N
H+ / MnO4 -
CH3CHOHCH3
propan-2-ol
(6)
(b)
F
CH3CH2CH2NH2
N
1-amino propane
excess
NH3
N
R
CH3CH2CH2Cl
1-chloropropane
Aq NaOH
HCl / ZnCl2
reflux
o
SOCl2
r
CH3CH2CH2OH
F
R H+ / Cr2O7 2-
R
propanoyl chloride
N
SOCl2
CH3CH2COOH
CH3CH2CCl
O
R
CH3CH2OH
Conc H2SO4
NH3
O
R
N
CH3CH2CNH2
propanamide
NH3
F
CH3CH2OOCCH2CH3
N
ethyl propanoate
(13)
5
3.
H
A
C
C
C
C
C
H
H
H
C
H
H
C
C
C
C
H
H
H
HBr
C
C
C
H
C
C
C
C
C
Br
H
C
H
H C
H
H
H
C
C
C
H
C
C
HBr
3-methyl but-1-ene
HBr
B
C
C
C
H
C
C
Br
H
Br H H
2-bromo-3-methyl butane
2,3-bromo methyl butane
alcoholic KOH
C
C
C
C
C
C
end of line because C
can exhibit cis/trans
isomerism
H
H
H
H C
H
C
C
H
NaOH (aq)
D
alcoholic KOH
alcoholic KOH
H
C
C
H
H
C
H
H
H
2-methyl but-2-ene
H
H C
H
H
H
C
C
C
C
H
O
H
H
H
acidified Dichromate
H
H
H
H C
C
C
H
O
C
H
H
C
H
H
C
C
C
NaOH (aq)
C
H
3-methyl butan-2-ol
E
C
C
C
C
C
O H
end of line because a
tertiary alcohol cannot be
oxidised
3-methyl butan-2-one
methyl butanone
(5)
6
4.
Systematic
name
Structural
formula
Compound M / g mol-1
Organic
class
A
60
B
58
CH3 -CO -CH3
C
102
(CH3 )2CHOOCCH3
D
42
CH3 -CH
CH2
propene
E
44
CH3 -CH2 -CH3
propane
F
123
5.
(a)
(b)
CH3 -CHOH -CH3
propan-2-ol
sec alcohol
propanone
ketone
isopropyl ethanoate
CH3 -CHBr -CH3
alkene
alkane
2-bromopropane
H
H
C
C
C
H
H
O
H
OH
H
H
C
C
C Cl
H
H
O
Compound B
Compound A
H
halo alkane
(15)
(1)
Primary
H
ester
H
H
H
C
C
O C C C H
H
H
O H H
H
H
Compound C
H
H
C
C
C NH2
H
H
O
Compound D
(4)
6.
CH3
C
O
CH2 CH2 CH2 CH2 CH3
O
(1)
There are others of course.
7.
(a)
3-methyl hex-2-enoic acid
(1)
(b)
CH2 CH3
H
C
H
H
C
C
CH3
trans pent-2-ene
H
CH3
C
CH2 CH3
cis pent-2-ene
(2)
8.(a)
7
CH3 CH2 CH2 CH
CH2
H2 O / H2 SO4
step X
pent-1-ene
CH3 CH2 CH2 CH CH3
OH
pentan-2-ol
reagent
H + Cr2O72 -
CH3 CH2 CH2 C CH3
O
pentan-2-one
(b)
CH3CH2CH2CH2CH2OH
(4)
(1)
8