This document is a chemistry exam containing multiple choice and long answer questions testing knowledge of organic chemistry concepts. It covers topics such as: - Distinguishing between enantiomers using Fischer projections. - Translating between Fischer, saw-horse, and Newman projections. - Assigning configurations of organic molecules as E or Z. - Explaining the reactivity and substitution patterns of organic reactions. - Describing concepts like stereoselectivity, asymmetric synthesis, and neighboring group participation. - Explaining reaction mechanisms and determining mechanisms using methods like crossover experiments and isotope effects. - Discussing the stereochemistry and conformations of organic molecules. - Comparing

1. Sp 5
NOVEMBER 2014 55701/MCR1A
Time : Three hours Maximum : 75 marks
PART A — (10  1 = 10 marks)
Answer any TEN questions.
Each answer should not exceed 50 words.
1. Which of the following fischer projections
represent enantiomers?
(a) (b)
(c) (d)
2. Translate the following fisher projections into
staggesed forms of saw horse and Newman
projections.
(6 pages)
COOH
OH
H
CH3
COOH
OH
H
H3C
CH3
H
OH
HOOC
OH
H
H
CH3
CH3
Cl
COOH
HO
H
CH3

2. Sp 5
55701/MCR1A
2
3. Assign the following as E or Z.
(a) (b)
4. Which of the following bromo cyclohexanones
exhibit higer C = 0 stretching frequency in IR
spectrum? Explain.
(a) and (b)
5. Write the more stable conformer of Cis 1,3–
dimethylcyclohexane comment on its optical
activity.
6. Chloromethyl methyl ether, 3
2OCH
ClCH ,
undergoes ready 1
N
S solvolysis reactions, even
though it is a primary substrate.
7. Which reagent would be more nucleoplilic towards
Br
CH3 in ethanol and why?
H
N
CH3 or 2
3 H
N
CH  .
⊝

3. Sp 5
55701/MCR1A
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8. Give an example of 2
N
S reaction where an
optically active substrate gives racemic product.
9. Diazotization of primary armatic amines should be
carried out in strongly acidic solutions. Explain.
10. Formulate the following :
11. The –ccl3 group is m-directing in electrophilic
substitution reaction of 3
5
6 CCl
H
C . Why?
12. What is Reimer-Tieman Reaction? Identify the
electrophile in this reaction.
PART B — (5  5 = 25 marks)
Answer any FIVE questions.
Each answer should not exceed 200 words.
13. Illustrate stereospecific and stereoselective
reactions.
14. Define the term asymmetric synthesis. State and
illustrate Cram’s rule of asymmetric induction.
NH2
NH2 NaNO2 / HCl

4. Sp 5
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15. Comment on the topic relationship between the
two faces of carbonyl group of 4-t-butyl
cyclohexanone.
16. Write a note on neighbouring group participation
in alphatic nuclephilic substitution reaction with
suitable examples.
17. Explain the following:
(a) Claisen condensation
(b) Von-Braun reaction.
18. Illustrate the usefulness of cross-over experiments
and isotope effect in the determination of reaction
mechanism with examples.
19. Predict the product and discuss its mechanism.
OH
CH3CN
(i) ZnCl2/HCl
O’C/ether
(ii) H3O+
[P.T.O.]

5. Sp 5
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5
PART C — (4  10 = 40 marks)
Answer any FOUR questions.
Each answer should not exceed 500 words.
20. Give a brief account on Geometrical isomerism.
How geometrical isomers were distinguished by
physical and chemical methods.
21. Write an essay on the stereochemistry and
conformation of Cis and trans-declain and
9-methyl declain.
22. Discuss the following:
(a) Substitution in norbornyl and bridge head
systems.
(b) Substitution by ambient nucleopliles.
23. Explain in detail about the possible mechanism in
the hydrolysis of ester.

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6
24. Explain the following:
(a) Hammet equation and Taft equation.
(b) Ziegler alkylation and Vilsmeyer–Hack
reaction.
25. Give a brief account on orientation and reactivity
in substituted benzene.
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