LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – CHEMISTRY
FIFTH SEMESTER – APRIL 2012
CH 5505 – ORGANIC FUNCTIONAL GROUPS – II
Date : 25-04-2012 Dept. No. Max. : 100 Marks
Time : 9:00 – 12:00
PART – A
Answer ALL the questions: (10 x 2 = 20)
- Why Nitrobenzene is often used as solvent in Friedel Crafts reaction.
- How will you prepare nitroethane by vapourisation method?
- Assign R and S configuration to the following:
- What are enantiomers? Give two properties of enantiomers.
- Explain Walden inversion using SN2 reaction.
- Explain keto-enol tautomerism exhibited by acetoacetic ester.
- What is Cope rearrangement?
- Give the products of the following reaction:
- What is isoprene rule? Indicate the isoprene units in the structure of α-pinene.
- Write the structure of Conine.
PART – B
Answer any EIGHT questions: (8 x5 = 40)
- Give the products obtained when Nitrobenzene is reduced in
- a) Strongly acidic solution
- b) Strongly alkaline solution.
- Using Hinsberg test,how will you distinguish between
N-methylaniline and N,N’ dimethyl aniline.
- Explain why pyridine is more basic than pyrrole.
- i) What is asymmetric synthesis?
- ii) How will you prepare (-) lactic acid from pyruvic acid?
- Discuss the optical isomerism exhibited by biphenyl compounds.
- How will you synthesize adipic acid from ethyl acetoacetate?
- How will you synthesize propionic acid from acetic acid using Arndt – Eistert
- Describe Hoffmann rearrangement. Discuss its mechanism.
- Describe Fries rearrangement and give its mechanism.
- Complete the following reactions.
- How will you synthesize nicotine from nicotinonitrile?
- What are the products obtained when Citral is subjected to oxidation with
alkaline KMnO4 followed by chromic acid?
PART – C
Answer any FOUR questions: (4 x 10 =40)
- i. How is Nitrobenzene prepared from benzene? Give its mechanism.
- How will you prepare o-dinitrobenzene and p-dinitrobenzene from Aniline?
- i. What is diazotisation? How is benzene diazonium chloride prepared in the
- Explain Gattermann and Sandmeyer reactions using suitable examples.
- i. Discuss Claisen rearrangement with a specific example . Give its mechanism.
- How will you prove that in Claisen rearrangement ,o-isomerisation takes place
with inversion of position?
- i. Describe the various methods for the resolution of racemic mixtures.
- Explain the phenomenon of racemisation taking a suitable example.
- i. How is Quinoline prepared by Skraup’s synthesis?
- Electrophilic substitution in pyrrole takes place at 2- position whereas in
pyridine at 3- position. Why?
- i. What are Alkaloids? How are they extracted from plants?
- How are Terpenes classified?
iii. What are the structural formula and uses of
- Menthol b. α-Pinene c. Camphor.