M.Sc. DEGREE EXAMINATION, NOVEMBER 2017
Third Semester
Chemistry
ORGANIC CHEMISTRY III
(CBCS 2014 onwards)
Time 3 Hours Maximum 75 Marks
Part A (10 x 2 20)
Answer all questions.
1. State octant rule.
2. What is cotton effect? Give an example.
3. List out the conditions for the molecule to be IR active.
4. What are isotope peaks? How are they used in mass
spectrometry?
5. What type of nucleic become NMR active? Give examples.
propylene,
1-butene.
7. How is Gilman's reagent prepared? Give any one
synthetic use of it.
8. What is Barton reaction?
9. Give the colour reactions to identify cholesterol.
10. Write down the applications of paper chromatography.
Sub. Code
4MCH3C1
AFF-4886
2
Wk 10
Part B x 5 25)
Answer all questions, choosing either or
11. Explain photoreduction with the help of its
mechanism.
12. Illustrate Woodward-Fieser rule with suitable
example.
Or
Explain the factors influencing group frequencies in
IR spectroscopy.
13. What are shift reagents? Explain in detail its role in
NMR study.
14. Give an account on the synthetic utility of
DCC
1,3-dithiane.
Or
Describe the formation and stability of free radicals.
15. Outline the synthetic steps involved in the
conversion of ergosterol to progesterone.
Or
Explain the working principle and application of
HPLC.
AFF-4886
3
Wk 10
Part C x 10 30)
Answer any three questions.
16. Describe the photo physical processes in
electronically excited molecules using Jablonski's
diagram.
Predict the products expected in the following photo
chemical reaction. x 1.5


17. Using suitable examples, explain Mc Lafferty
rearrangement.
Suggest molecular formulae for the fragment ions
obtained from isobutane, m/e 43, 28 ,27.
18. Discuss in brief on Woodward and prevost method
of hydroxylation.
Predict the product(s) in the following reactions.


Explain Hundsdiecker reaction.
20. How will you convert cholestrol into testosterone?

Write notes on column chromatography.
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