CHEM1002
2014-N-8
November 2014
• Complete the following table. Make sure you give the name of the starting material
where indicated.
STARTING MATERIAL
REAGENTS/
CONDITIONS
NaOH(aq)
Cr2O72- / H+
concentrated H2SO4
CONSTITUTIONAL
FORMULA(S) OF MAJOR
ORGANIC PRODUCT(S)
Marks
3
CHEM1002
2013-N-7
November 2013
• Complete the following table. Make sure you give the name of the starting material
where indicated.
STARTING MATERIAL
REAGENTS/
CONDITIONS
NaOH
CONSTITUTIONAL
FORMULA(S) OF MAJOR
ORGANIC PRODUCT(S)
Marks
1
CHEM1002
•
2013-N-9
November 2013
The structure of (–)-linalool, a commonly occurring natural product, is shown below.
Give the constitutional formula of the organic product formed from (–)-linalool in
each of the following reactions. NB: If there is no reaction, write "no reaction".
Reagents / Conditions
Na2Cr2O7 in aqueous acid
Na, then CH3Br
Constitutional Formula of Product
no reaction
Marks
2
CHEM1002
2012-N-10
November 2012
• Butanone is treated first with lithium aluminium hydride, LiAlH4, in dry ether and
then with aqueous acid to yield the alcohol, A.
A is treated with concentrated sulfuric acid to give mainly the alkene B and two other
alkenes C and D. Alkenes B and C are diastereomers, B and D (and C and D) are
constitutional isomers. Give the structures for C and D and give systematic names for
B, C and D.
B
C
D
Name: (E)-2-butene
Name: (Z)-2-butene
Name: 1-butene
Marks
4
CHEM1002
2010-N-7
November 2010
• Give the name of the starting material where indicated and the constitutional
formula(s) of the major organic product(s) formed in each of the following reactions.
NB: if there is no reaction, write "no reaction".
Cr2O72 / H
OH
Name: 2,4-dimethylpentan-2-ol
conc. H2SO4
OH
heat
no reaction
Marks
3
CHEM1002
2009-N-8
November 2009
• Give the name of the starting material where indicated and the constitutional formula
of the major organic product formed in each of the following reactions.
Na2Cr 2O7 / H
OH
COOH
Name: 3-methyl-1-butanol
Br
conc. KOH, ethanol
heat
Name: 1-bromobutane
Br
Br
N(CH3)3
N
Marks
5
CHEM1002
•
2009-N-9
November 2009
Marks
Consider the following reaction sequence.
6
C
CH3OH
O
O
OH
Cl
B
aqueous NaOH
excess
D
(CH3) 2NH
1. LiAlH4
2 equiv.
2. H3O
E + F
A
Give the reagent B and draw the constitutional formulas of the major organic
products, A, C, D, E and F, formed in these reactions.
A
D
O
OH
O
B
•
E
O
SOCl2
N
C
•
F
O
Cl
OCH3
H N H
CHEM1002
2008-N-7
November 2008
• Give the name of the starting material where indicated and the constitutional formula
of the major organic product formed in each of the following reactions.
Br
N C
C
N
Name: bromocyclopentane
(Nucleophilic substitution by Br- by CN-)
Br
conc. ethanolic KOH
heat
(Base catalysed elimination of H-Br to form a C=C, following Zeitsev’s rule).
Marks
3
CHEM1002
•
2008-N-9
November 2008
Marks
Consider the following reaction sequence.
6
COOCH3
dilute H2SO4
heat
SOCl2
A
Reagent D
CH2OH
B
Reagent C
CON(CH3)2
conc. H2SO4
E
heat
Reagent F
Give the reagents C, D and F and draw the structures of the major organic products,
A, B and E, formed in these reactions.
A
D
COOH
(1). LiAlH4 / dry ether
(2). H+ / H2O
(Reduction of carboxylic acid to
primary alcohol).
(Hydrolysis of an ester to a
carboxylic acid).
B
E
O
Cl
(Formation of an acid chloride from
a carboxylic acid).
(Acid catalysed elimination of H-OH
(“dehydration”) to form C=C).
ANSWER CONTINUES ON THE NEXT PAGE
CHEM1002
2008-N-9
November 2008
F
C
CH 3
H N
CH 3
(Formation of amide from acid
chloride).
H2 / Pd/C
(Reduction of alkene to alkane).
CHEM1002
2008-N-10
November 2008
• Show clearly the reagents you would use to carry out the following chemical
conversion. Two steps are required. Give the structure of the intermediate
compound.
Br
Br
HBr
CCl4 solvent
hot KOH
ethanol solvent
(Addition of H-Br
across C=C, f ollowing
Markovnikov's rule).
(Base catalysed
elimination of H-Br
to form C=C).
How could you distinguish between the starting material and the product by 13C NMR
spectroscopy?
The starting material has 3 different carbon environments so will give 3
resonances in the 13C NMR.
2
1
3
Br
The produt has 2 different carbon environments so will give 2 resonances in the
13
C NMR.
Br
2
1
1
The two carbon atoms labelled as ‘1’ are equivalent.
Marks
5
CHEM1002
2007-N-6
November 2007
• Give the name of the starting material where indicated and the constitutional formula
of the major organic product formed in each of the following reactions.
Na2Cr 2O7 / H
OH
O
Name: 2-methylcyclohexanol
conc. ethanolic KOH
heat
Br
Name: 2-bromobutane
O
O K
Br
O
O
Marks
5
CHEM1002
•
2007-N-8
November 2007
Marks
6
Consider the following reaction sequence.
O
Br
OH / H2O
reagent B
OH
A
NaOH
reagent D
C
O
(CH3CH2)2NH
F
E
Cl
CH3OH
Give the reagents B and D and draw the structures of the major organic products,
A, C, E and F, formed in these reactions.
A
D
OH
B
SOCl2 / heat
E
O
Cr2O72– / H+
O
C
F
O
O
O
N
CH3OH
CHEM1002
2006-N-6
November 2006
• Give the name of the starting material where indicated and the constitutional formula
of the major organic product formed in each of the following reactions.
Cr2O7
2
/H
OH
O
Name: 2-butanol
(Dehydration leading to
more substituted double
bond: Zeitsev's rule)
conc. H2SO 4
heat
OH
CN
Br
N C
Name: bromocyclohexane
Marks
5
CHEM1002
•
2006-N-8
November 2006
Marks
6
Consider the following reaction sequence.
B
1) LiAlH4
2) H / H2O
O
OH
reagent A
NaOH
C
H
O
reagent D
E
excess
H2NCH 3
Cl
CH3OH
F
O
Give the reagents A and D and draw the structures of the major organic products,
B, C, E and F, formed in these reactions.
A
D
Cr2O72- / H+
SOCl2
B
E
O
OH
CH3
N
H
C
F
O
O
CH3
O
O
CHEM1002
2005-N-6
November 2005
 Give the name of the starting material where indicated and the constitutional formula
of the major organic product formed in each of the following reactions.
Br
Br
Name: 1-methylcyclohex-1-ene
OH
Markovnikov addition - H
becomes attached to carbon with
fewer alkyl groups attached.
O
OH
Na2Cr2O7 / H
Name: cyclohexanol
Marks
5
CHEM1002
2005-N-8
November 2005
 Classify the starting materials of the following reactions as nucleophile or electrophile
and indicate with  and  the polarisation of the C–Br and C=O bonds.
CH3
H3C N
δ
Br
+
CH3
δ+
CH3
H3C N CH3
Br
electrophile
nucleophile
H
nucleophile
+
H3C δ δ
C O
H3C
H3C
H C O
H3C
H3C
H C O
H
H3C
H
electrophile
6
 Consider the following reaction sequence.
O
OH
NaOH
1) LiAlH 4
2) H
B
SOCl2
D
4
CH3
CH3
A
Marks
excess methanol
C
HN(CH 3)2
E
conc. HCl / heat
F
Draw the structures of the major organic products, A-F, formed in these reactions.
A
D
O
O
C
C
O
B
OCH3
E
CH2OH
O
C
N
CH3
CH3
C
F
O
O
C
C
Cl
OH
+
NH2(CH3)2
CHEM1002
2005-N-8
November 2005