LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2010

CH 5505 – ORGANIC FUNCTIONAL GROUPS – II

 

 

 

Date : 29-10-10                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART – A

 

Answer ALL questions.                                                                                             (10 x 2 = 20 marks)

 

1. Explain why nitration of nitrobenzene is more difficult than that of benzene.
2. Account for the fact that Nitromethane is acidic.
3. Give the IUPAC name of
4. CH₃-NH-C₂H₅  ii.CH₃-N(CH₃) –CH₃.
5. What are diastereomers?Explain with an example.
6. Explain Walden inversion using S_N2 reaction.
7. Show how will you prepare 3-methylpentanoic acid from diethyl malonate.
8. What is Cope rearrangement.
9. Give the products of the following reaction

    

    ii.

       

 

9. What is isoprene rule?
10. Write the structure of piperic acid.

 

PART – B

Answer any EIGHT questions                                                                                    (8 x 5 = 40 marks)

 

11. Give the products obtained when Nitrobenzene is reduced electrolytically in
12. Strongly acidic solution.
13.   Strongly alkaline solution.
14. Arrange the following in decreasing order of basicity giving suitable reasons.

       Aniline, p-Nitroaniline , m-Nitroaniline and  Diphenylamine.

13. What is coupling reaction?Give the products obtained when benzene diazonium

      chloride reacts with i. phenol  ii. N, N-dimethylaniline.

14. i. What is asymmetric synthesis?
15. How will you prepare (-) lactic acid from pyruvic acid?
16. Discuss the optical isomerism exhibited by biphenyl compounds.
17. How will you synthesize n-butyric acid from ethyl acetoacetate?
18. How will you synthesize propionic acid from acetic acid using Arndt – Eistert

      reaction.

18. Describe Pinacole –Pinacolone rearrangement.Discuss its mechanism.
19. Describe Curtius rearrangement and give its mechanism.
20. Give the mechanism and orientation of electrophilic substitution in pyridine.
21. How will you synthesize nicotine from nicotinonitrile.
22. 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 marks)

 

23. i. How is Nitrobenzene prepared from benzene? Give its mechanism.             (5)
24. How will you prepare o-Nitroaniline and p-Nitroaniline from Aniline      .                                   (5)

 

24. i. How is benzene diazonium chloride prepared in the laboratory. (4)
25. Explain Gattermann and Sandmeyer reactions using suitable examples.                         (4)

      iii. How will you prepare Phenol from benzene diazonium chloride.                                                 (2)

 

25.i. Discuss Claisen  rearrangement with a specific example . Give its mechanism.                  (5)

1. How will you prove that in Claisen rearrangement ,o-isomerisation takes place

         with inversion of position.                                                                                                                   (5)

 

26. i. Describe any one method for the resolution of racemic mixtures.             (4)
27. Explain by giving an example the phenomenon of racemisation.                                       (3)

• Assign R and S configuration to the following Fischer projection.                  (3)

 

1.                                                         iii.

                        

 

27. i. How is Quinoline prepared by Friedlander synthesis using o-Amino benzaldehyde. (5)

      ii.Complete the following reactions.                                                                                                       (2)

        a.

           

 

        b.

           

       

      iii.Explain why pyridine is more basic than pyrrole?                                                                          (3)

28.i.What are Alkaloids? How are they extracted from plants.                                                                (5)

     ii.What are the structural formula and uses of

1. Menthol b. α-Pinene  c. Camphor.                                                                                              (5)

 

 

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