LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

GH 11

THIRD SEMESTER – APRIL 2008

CH 3502 – ORGANIC FUNCTIONAL GROUPS – I

 

 

 

Date : 26/04/2008                Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

PART – A

                                                                        (10 x 2 = 20 marks)

Answer ALL the questions.

1. Explain why 1⁰ alkyl halides undergo nucleophitic substitution only by S_N2.
2. Name the products obtained in the addition of HBr to propere in the absence and presence of peroxide.
3. What happens when acetophenone is treated with I₂ / NaOH?
4. Why p-nitrophenol has higher boiling point than o-nitrophenol?
5. What are mixed ethers? Give examples.
6. How is anisole prepared? What happens when anisole is treated with excess of HI?
7. Name the products obtained form 2-hexanone in Norrish type II reaction.
8. What is Cannizzaro’s reaction?
9. Compare and account for the acidity of acetic acid, prop ionic acid and chloroacetic acid.
10. What is the action of heat on malonic and succinic acids?

 

PART – B

                                                                        (8 x 5 = 40 marks)

Answer any EIGHT questions.

1. Give any two methods of preparation of chlorobenzene. Starting from chlorobenzene how are the following compounds prepared?

1. a) o-dichlorobenzene b) aniline      c) DDT

1. Discuss the effect of nature of substrate, nucleophile and solvent in nucleophilic substitution.
2. a) Account for the acidity of phenol

1. b) How would you prepare the following compounds from phenol?
2. i) o – Cresol ii) Benzene iii) Phenyl acetate.

1. Explain the nitration of Phenol with Mechanism.
2. How are alcohols prepared by hydroboration method? Give the mechanism of the reaction.
3. a) Why are ethers less reactive than epoxides?

1. b) How is ethylene oxide prepared? How does it react with methanol and ammonia?

1. a) Write the IUPAC names of ethyl methyl ether and anisole.

1. b) Give any two methods of preparation of diethyl ether. Mention a reaction where ether behaves as a Lewis base.

1. What is Reformatsky reaction? How is it useful in organic synthesis?
2. Discuss Norrish type I reaction.
3. Give the products of the following reactions.

1. Benzaldehyde +
2. Acetaldehyde + Malonic ester
3. Benzaldehyde
4. Acetone +
5. Acetaldehyde +Malonic ester

 

1. a) What is meant by transesterification?

1. b) Discuss the action of heat on and – amino acids.

1. Give any two methods of preparation of adipic acid. Write its IUPAC name. How would you convert adipic acid into cyclopentanone and NYLON-6,6?

 

PART – C

                                    (4 x 10 = 40 marks)

Answer any FOUR questions.

1. Explain E1 mechanism of dehydrohalogenation of alkyl halides. Discuss the orientation and reactivity of alkyl halides in dehydrohalogenation.
2. a) Identify the products in the following sequence of reactions

Isopropyl alcohol ABC D

1. b) Discuss the following reactions of phenol
2. i) Coupling reaction ii) Reimer – Tiemann reaction

1. a) Explain Williamson’s synthesis of ethers with mechanism.

1. b) Discuss the cleavage of ethers with HI

1. Discuss the following reactions with mechanism

1. a) Wittig reaction b) Benzoin condensation

1. a) How do you convert benzaldehyde into cinnamaldehyde? Explain with mechanism.

1. b) Arrange the following compounds in the increasing order of acidity. Give reason. Benzoic acid, p-toluic acid, p-nitrobenzoic acid and p-chlorobenzoic acid.

1. a) How is acetyl chloride prepared from acetic acid? How are the following compounds prepared from acetyl chloride?

1. Acetaldehyde ii) Acetophenone  iii) Acetone
2. b) Give the mechanism of esterification.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

DB 07

   B.Sc. DEGREE EXAMINATION – CHEMISTRY

THIRD SEMESTER – November 2008

CH 3502 / CH 4500 – ORGANIC FUNCTIONAL GROUPS – I

 

 

 

Date : 06-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

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

 

1. How is 1-bromo-2-methylpropane prepared from 2-methylpropene?
2. Write one example each for a)S_N1 and b)S_NAr reactions.
3. How are the following distinguished using a characteristic chemical test?

a)benzyl alcohol & ethanol     b)phenol & benzyl alcohol

4. How is benzene converted into p-nitrophenol?
5. Write the IUPAC name for a)anisole b)methyl isopropyl ether.
6. How is methyl isopropyl ether prepared using Williamson’s method?
7. Write one example each for a)Norish type-I reaction and b)Wolf-Kishner reduction.
8. Write equations to explain the preparation of a)propan-1-ol using ethanal.
9. Write IUPAC names for a)oxalic acid and b)cinnamic acid.
10. What is trans-esterification? Write one example.

 

 

PART – B

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

 

11. Explain the difference in stereochemistry between n-butyl iodide and t-butyl iodide during nucleophilic substitution reaction, by writing suitable mechanisms.
12. What happens when ethyl iodide is reacted with: a)alc KOH b)alc AgCN c)sodium phenoxide  d)moist silver oxide  e)sodium acetate?
13. Write a suitable mechanism for hydroboration – oxidation reaction. (3)

Explain how 2-phenylethanol prepared by this method.                                (2)

14. a)Arrange the following in the increasing order of acidity: ethanol, methanol, benzyl alcohol and phenol.             (2)

b)Explain why sodium phenoxide is a weaker base than sodium ethoxide.   (3)

15. How is phenol converted into a) salicylaldehyde b) benzene c)aspirin         (2+1+2)
16. Predict the major product when propene oxide is reacted with a)NaNH₂ / NH₃

b)H₃O⁺                                                                                                           (5)

17. Write a suitable mechanism for Williamson’s synthesis                                  (5)
18. How are the following converted? a)CH₃CH₂OH à CH₃CH=CHCHO

b)CH₃COOH à CH₃COCH₃  c)C₆H₅CHO à C₆H₅CH=CH₂                     (2+1+2)

19. How would you distinguish the following? a)methanol & ethanol b)methanal & benzaldehyde  c)acetophenone & benzaldehyde                                                                    (1+2+2)

 

20. Write a suitable mechanism for Cannizaro reaction. Identify the rate determining step.

(4+1)

21. How is benzaldehyde converted into benzoin? Write equation. (3)

In which case the α-hydrogen is more acidic between ethanal and propanone.  Why? (2)

22. How are the following compounds prepared? a)acetic acid into malonic acid b)phthalic acid from naphthalene  c)propanoic acid into acrylic acid.                                 (2+1+2)

 

 

PART – C

Answer any FOUR questions.                                                                      (4 x 10 =40 mks)

 

23. A)Point out the differences between S_N1 & S_N2 reactions with respect to

a)effect of using a polar solvent  b)kinetics  c)reactivity of alkyl halides.             (6)

B)How is n-propyl bromide prepared from a)propene b)ethyl bromide         (1.5 + 2.5)

24. A)How are the following compounds prepared from ethanol? a)CHI₃ b)ethanoic acid  c)phenyl ethanoate  d)ethyne  e)methanal                                                              (5 x 2 =10)
25. A)How is ethane oxide prepared? (4)

B)Write a suitable mechanism for the reaction:

CH₃CHO + CH₃CH₂CHO à CH₃CHOHCH(CH₃)CHO                 (6)

26. A)Write a note on a)Jablonskii diagram b)use of a cyanohydrin (3+3)

B)Predict the product when alkaline KMnO₄ is reacted with maleic acid and fumaric acid.

(2+2)

27. A)Arrange the following in the increasing order of pKa values:

benzoic acid, o-nitrobenzoic acid, m-nitrobenzoic acid and p-nitrobenzoic acid. (4)

B)How are the following prepared from acetyl chloride?  a)ethanal  b)acetophenone

c)acetic anhydride                                                                                                   (6)

28. A)What happens to the acid strength along the homologous series of carboxylic acids?

Explain.                                                                                                           (1+3)

B)Write note on the following: a)Knoevenagel reaction  b)action of heat on α, β and γ-hydroxy acids  c)Use of Zn-Hg / HCl in organic synthesis.                                      (3×2=6)

 

 

 

 

CH 5505 – ORGANIC FUNCTIONAL GROUPS II

PART – A

Answer ALL the questions                                                                        (10 x2 = 20 marks)

1. Write the isomers of nitrobutane.
2. What is diazotization?
3. Explain with example D and L notation.
4. Mark R and S configuration for the following compounds

1.             ii)

 

1. Write the synthesis of acetoacetic ester by Claisen condensation.
2. How is diazomethane prepared?
3. What is Isoprene rule?
4. What is Fries rearrangement?
5. What are sulpha drugs?
6. Draw the structures of the following compounds  (i) α-pinene          ii) Camphor

 

PART – B

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

1. Explain the mechanism of Gomberg reaction.
2. Which of the following is more basic? p-nitro aniline or  p-Toludine.  Explain
3. Give an account of the optical activity of biphenyls.
4. Explain Walden inversion.
5. Establish keto-enol tautomerism exhibited by acetoacetic ester.
6. How will you synthesise the following from acetoacetic ester (i) Acetyl acetone  (ii) Crotonic acid?
7. Write briefly on Beckmann rearrangement.
8. How is isoquinoline prepared?
9. How does pyridine react with         i) NaNH₂      ii) n-ButylLithium        iii) CH₃ COCl/A1C1₃.
10. Explain the electrophillic substitution of reactions of pyrrole.
11. How will you prepare 1, 3, 5 trinitrobenzene?
12. Explain asymmetric synthesis.

 

 

 

PART – C

Answer any FOUR questions                                                                  (4 x 10 = 40 marks)

1. (i) How will you separate the mixture of amines by Hinsberg method.

(ii)Explain the coupling reactions of benzene diazonium chloride.

1. Explain the various methods of Resolution of a racemic mixture.
2. Write the preparation, properties and uses of diazoacetic ester.
3. Explain any two following rearragngements with mechanism

(i) Benzilic      (ii) Cope                     (iii) Curtius

27. i) Name the following compounds based on R and S configuration and represent it in

flying wedge,  sawhorse and Newmann projection formula.

 

 

(ii) Differentiate of enantiomersfrom diastereomers.

28. (i) Explain Hoffmann’s rearrangement.

(ii) Outline the synthetic utility of Benzene diazonium chloride.

 

 

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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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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – CHEMISTRY

THIRD SEMESTER – NOVEMBER 2010

CH 3502 – ORGANIC FUNCTIONAL GROUPS – I

 

 

 

Date : 30-10-10                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART – A

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

 

1. Arrange the following compounds in increasing order of reactivity towards S_N2

          reaction. Give reasons.

          t-butyl chloride, n-propyl chloride.

 

2. How is benzyl chloride prepared from benzaldehyde.

 

3. Why does phenol have higher boiling point than toluene.

 

4. Complete the reaction

 

           

 

5. Give the IUPAC name of the following compounds

 

 

6. How will you prepare phenyl methyl ether from phenol using Williamson’s synthesis?

 

7. What happens when calcium acetate is heated? Give its equation.

 

8. What is Norrish type –I reaction.

 

9. What is trans esterification.

 

10. Arrange the following in terms of increasing acid strength and give reasons.

           Propionic acid , 2chloropropionic acid , 2 fluoropropionic acid.

 

PART – B

Answer any EIGHT questions                                                                  (8 x 5 = 40)

11. Give a mechanism for the reaction of tert.butyl bromide with aqueous NaOH to

  form tert.butyl alcohol.

12. Explain Saytzeff rule and Hofmann rule with an example.
13. How is phenol prepared from Cumene.
14.    Although both phenol and alcohols contain hydroxyl group, Phenol is acidic    

            whereas aliphatic alcohols are not acidic – Explain.

15. How will you prepare primary,secondary and teritiary alcohols from Grignard

            reagent.

16. How is ethyl methyl ether prepared by Williamson’s synthesis.What  type of

            mechanism is followed.

17. Write a short note on cleavage of ethers by acids.
18. Discuss the mechanism of Cannizaro reaction.
19. Explain crossed aldol condensation with an example.
20. What is Wittig reaction ? Explain its mechanism.
21. Discuss the geometric isomerism of unsaturated dicarboxylic acids.
22. Explain the mechanism of alkaline hydrolysis of esters.

 

                                                        PART – C

Answer any FOUR questions.                                                                    (4 x 10 =40)

 

23. a) Explain the fact that allyl chloride undergoes substitution reaction by SN1 

                mechanism whereas n-propyl chloride reacts by SN2 mechanism.

1.   b) Discuss the Mechanism of E1 and E2 reactions of alkyl halides.

                     

24. a) Give the mechanism of Reimer Tiemann reaction and Kolbe’s reaction.
25. b) How is phenolphthalein prepared from phenol?

 

25. i. How is acetic acid converted to ethyl acetoacetate.
26.          How would you prepare the following compounds from acrylic acid.
27. Propionic acid.
28. Glyceric acid.
29. 2- bromo propionic acid.

 

26. a) How is ethylene oxide prepared?
27.     b) How does diethyl ether react with

                 i.O₂/long contact    ii.PCl₅

1.  c) How does ethylene oxide react with the following reagents:
2.        H₂O/H⁺   ii. HBr   iii.CH₃CH₂OH  iv.NH₃.

 

27.   i. How will you prepare the following compounds
28.               a) 2-propanol from CH₃CHO
29.             b) Lactic acid from CH₃COCH₃
30.           Discuss the mechanism of Reformatsky reaction.         

 

28. a) Write notes on Clemmensen reduction and Wolff-Kishner reduction.
29. b) How will you synthesize cinnamic acid using Perkin’s and Knoevenagel

                reactions.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

THIRD SEMESTER – APRIL 2011

CH 3502/CH 4500 – ORGANIC FUNCTIONAL GROUPS – I

 

 

 

Date : 12-04-2011              Dept. No.                                                    Max. : 100 Marks

Time : 1:00 – 4:00

 

SECTION-A

ANSWER ALL QUESTIONS                                                                   (10×2=20)

1. What is Saytzeff’s rule? Give an example.
2. What is Sandmeyer reaction?
3. What is Clemmensen reduction?
4. What happens when acetone is treated with I₂ and NaOH?
5. Name the products obtained when anisole is treated with HI.
6. Explain why anisole cannot be prepared by the reaction of phenyl iodide and

sodium methoxide.

7. What is crossed Cannizzaro reaction?
8. How do you convert benzaldehyde  into cinnamaldehyde?
9. What is transesterification?
10. How is succinic acid prepared? Name the product obtained  when it is

heated.

 

SECTION-B

  ANSWER ANY EIGHT QUESTIONS                          (8×5=40)

11. Compare S_N1 and S_N2 reaction mechanisms.
12. Write notes on Wurtz-Fittig reaction.
13. How are alcohols prepared by hydroboration? Give  an example.
14. Why o-nitrophenol has a lower boiling  point  than p-nitrophenol?
15. How do you convert phenol into
16. a) picric acid b) salicylaldehyde

 

16. Discuss the mechanism of cleavage of ethers by HI.
17. Explain Williamson’s synthesis of ethers.
18. Discuss Norrish type-I reaction.
19. Discuss the mechanism of Wittig reaction and its uses in organic synthesis.
20. Explain Wolf-Kishner reduction with its mechanism.
21. Give any two methods of preparation of adipic acid.
22. Discuss the mechanism of acid catalysed hydrolysis of esters.

 

SECTION-C

       ANSWER ANY FOUR QUESTIONS                             (4×10=40)

 

23. Discuss the E1 mechanism for elimination reactions of alkyl halides.
24. a) Why p-nitrophenol is more acidic than phenol whereas p-cresol is less

acidic than phenol?                                                                                     (6)

1. b) What will be the product obtained when  p-cresol is treated with

CH₃COCl  and AlCl₃. Give reason.                                                          (4)

25. a) Explain why epoxides are more reactive than ethers. (4)
26. b) Name the products obtained when ethylene oxide is treated with

i)H₂O/H⁺          ii)C₂H₅OH/H⁺                iii)NH₃                                              (6)

26. Discuss the following reactions.
27. a) Benzoin condensation b) Reformatsky reaction (5+5)
28. How will you bring about the following conversions?
29. i) Salicylic acid into aspirin ii) Malonic acid into carbon suboxide

iii) Phthalic acid into phthalimide    iv) lactic acid into pyruvic acid

(v) acrylic acid into acrylamide.

28. a) Explain Norrish type-II reaction with an example.
29. b) How do maleic and fumaric acids differ in their properties?                     (5+5)

 

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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)

 

1. Why Nitrobenzene is often used as solvent in Friedel Crafts reaction.
2. How will you prepare nitroethane by vapourisation method?
3. Assign R and S configuration to the following:

   

                                                

4. What are enantiomers? Give two properties of enantiomers.
5. Explain Walden inversion using S_N2 reaction.
6. Explain keto-enol tautomerism exhibited by acetoacetic ester.
7. What is Cope rearrangement?
8. Give the products of the following reaction:

      

9. What is isoprene rule? Indicate the isoprene units in the structure of α-pinene.
10. Write the structure of Conine.

         

PART – B

Answer any EIGHT questions:                                                                 (8 x5 = 40)

 

11. Give the products obtained when Nitrobenzene is reduced in
12. a) Strongly acidic solution
13.  b) Strongly alkaline solution.
14. Using Hinsberg test,how will you distinguish between

       N-methylaniline and N,N’ dimethyl aniline.

13. Explain why pyridine is more basic than pyrrole.
14. i) What is asymmetric synthesis?
15. ii) How will you prepare (-) lactic acid from pyruvic acid?
16. Discuss the optical isomerism exhibited by biphenyl compounds.
17. How will you synthesize adipic acid from ethyl acetoacetate?
18. How will you synthesize propionic acid from acetic acid using Arndt – Eistert

      reaction.

18. Describe Hoffmann rearrangement. Discuss its mechanism.
19. Describe Fries rearrangement and give its mechanism.
20. Complete the following reactions.

 

       

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)

 

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

 

24. i. What is diazotisation? How is benzene diazonium chloride prepared in the

         laboratory?

1. Explain Gattermann and Sandmeyer reactions using suitable examples.

 

25. i. Discuss Claisen rearrangement with a specific example . Give its mechanism.
26. How will you prove that in Claisen rearrangement ,o-isomerisation takes place

         with inversion of position?

 

26. i. Describe the various methods for the resolution of racemic mixtures.
27.    Explain the phenomenon of racemisation taking a suitable example.

 

27. i. How is Quinoline prepared by Skraup’s synthesis?
28. Electrophilic substitution in pyrrole takes place at 2- position whereas in

          pyridine at 3- position. Why?

 

28. i. What are Alkaloids? How are they extracted from plants?
29. How are Terpenes classified?

       iii. What are the structural formula and uses of

1. Menthol b. α-Pinene  c. Camphor. 

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

THIRD SEMESTER – APRIL 2012

CH 3502 – ORGANIC FUNCTIONAL GROUPS – I

 

 

 

Date : 24-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART – A

       Answer all the questions:                                                                                   (10 x 2 = 20 marks)

1. Vinyl halides are less reactive towards nucleophilic substitution reaction. Why?
2. Arrange the following bromides in the order of ease of dehydrohalogenation by alc. KOH.

 

 

 

3. What happens when propanone reacts with CH₃MgBr followed by hydrolysis?
4. Convert aniline to phenol.
5. Give the IUPAC names of the following ethers:

 

 

6. What happens when anisole( methoxy benzene) is hydrolysed with HI? Write the reaction.
7. Identify the compounds A and B:

H₂/Pd, BaSO₄                         HCN

C₆H₅COCl  ——————–→  A  ——————–→ B.

 

8. Two isomeric compounds A and B, with molecular formula C₃H₆O , form oxime with hydroxyl

amine.  Tollens test is answered by compound B only and iodoform  test is answered by compound

A only. Give the structures of A and B and state reason.

 

9. What is trans-esterification reaction.

 

10. Why is α-chloroacetic acid more acidic than chloroacetic acid ?

 

SECTION – B

Answer any eight questions:                                                                                    (8 X 5 = 40 marks)

11. Explain the reactions involved in the free radical chlorination of methane.
12. Predict the major product of the following reaction and explain.

(CH₃)₃ C CH= CH₂    + HBr  ————→ ?

13. Explain Reimer-Tiemann reaction.
14. Convert phenol to : i). benzaldehyde, ii) benzoic acid.                                           (2.5 + 2.5)
15. Describe the mechanism of hydroboration-oxidation of propene to 1-propanol.
16. What happens when tert-butyl methyl ether is hydrolysed using HI? Explain.
17. Write the mechanism of acid catalysed ring opening of ethylene oxide.
18. Explain Wittig reaction with a suitable example. Bring out the advantage of this reaction.

 

 

19. What are the products formed when acetophenone reacts with each of the following compounds?

Write the reactions.

2. i) LiAlH₄ in THF followed by hydrolysis ,        ii) HCN.                                                      (2 x 2.5)
3. Write a short note on Norrish type I reactions.
4. Differentiate between maleic and fumaric acids.
5. Write a brief account on the action of heat on α, β hydroxy acids.

SECTION – C

Answer any four questions:                                                                                     (4 X 10= 40 marks)

23. a) Describe E₁ mechanism with an example.
24. b) 2, 4 –dinitro chloro benzene undergoes nucleophilic substitution much faster than              Explain your answer.
25. a) Explain Kolbe’s reaction with mechanism.
26. b) Carry out the following conversions:
27. i) (CH₃)₂ CH CH₂OH ——–→  (CH₃)₃COH
28. ii) (CH₃)₃CBr ——————-→    (CH₃)₂ CH CH₂                                                 (2.5 + 2.5)
29. a) Describe alkoxymercuration and demercuration procedure for the synthesis of ethers

with an example.

1. b) How are the following compounds prepared from ethylene oxide?
2. i) butan-1-ol             ii)  2-methoxy ethanol.                                                                        (2+3)
3. Write a short note on :
4. a) Michael reaction b) Perkin’s reaction                                                                             (5+5)
5. Provide any one method to prepare the following compounds.
6. i) succinic acid ii) cinnamic acid iii) crotonic acid         iv) phenyl acetate
7. v) phthalic anhydride                                                                                                                      (5 x 2)
8. Compound A with molecular formula C₇H₆O on treatment with con.NaOH gives compounds B and
9. B on oxidation gives back A. A answers Tollens test but not Fehing’s test. Compound C on

acidification gives D (C₇H₆O₂). D gives brisk effervescence with aqueous NaHCO₃ and reaction with

ethanol in the presence of dil.H₂SO₄ gives a sweet smelling compound E. Identify A, B, C, D and E

and write the reactions involved.  Write all possible isomers of A.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc., DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2012

CH 5505 – ORGANIC FUNCTIONAL GROUPS – II

 

 

 

Date : 01-11-2012              Dept. No.                                        Max. : 100 Marks

Time : 9.00 – 12.00

 

PART – A

Answer ALL questions:                                                                                            (10 × 2 = 20)

 

1. How will you prepare ethylamine by Gabriel phthalimide synthesis?
2. How will you prepare diphenyl amine?
3. Methyl amine is more basic than aniline.Explain.
4. What are erythro and threo isomers?
5. Are all substances with chiral atoms optically active and resolvable?Explain.
6. What is meant by tautomerism?Give an example.
7. Give an example of molecular rearrangement involving migration of a group from oxygen atom to aromatic ring.
8. What is isoprene rule?
9. What are alkaloids?
10. Suggest any two tests to prove the presence of alkaloids.

 

PART – B

Answer any EIGHT questions:                                                                                   (8 × 5 = 40)

 

11. Arrange the following compounds in decreasing order of basicity and give reasons

for your answer.

Aniline , p-nitro aniline , m- nitro aniline , p-methyl aniline

12. Starting from aniline how will you synthesize the following?
13. i) sulphanilic acid
14. ii) benzoic acid

iii) phenyl isocyanate

13. Explain why racemic tartaric acid can be resolved but not meso tartaric acid. Give the chemical method of resolution.
14. Differentiate between enantiomers and diastereomers by taking suitable examples.

 

15. What happens when the following pair undergoes Claisen condensation?

Ethyl formate and ethyl acetate. Suggest a suitable mechanism.

16. What do you understand by active methylene group? Highlight its significance in organic synthesis.
17. Discuss the mechanism of pinacol – pinacolone rearrangement and give the evidence for carbonium ion intermediate.
18. Discuss Claisen rearrangement and give suitable evidence to confirm that the rearrangement is intramolecular.
19. Electrophilic substitution takes place in C-2 position and not in C-3 position in Furan. Explain.
20. Outline the synthesis of nicotine.
21. Explain the role of Herzig-Meyer method and Zeisel’s method in the structural elucidation of alkaloids.
22. Discuss the mechanism of nitration of benzene and explain why nitro group is a

deactivating group.

 

                                                            PART – C      

Answer any four questions:                                                                                    (4 × 10 = 40)

 

23. Give an example for the following name reaction.
24. Sandmeyer reaction ii)  Gomberg reaction

• Gattermann reaction iv) Carbylamine reaction

1. Schiemann reaction

 

24. a) How will you synthesize ortho and meta dinitro benzene from benzene . (6)
25. b) How will you distinguish primary secondary and tertiary amines by Hinsberg

method.                                                                                                                                 (4)

 

25. a) Explain asymmetric synthesis with suitable examples. (6)
26. b) Discuss the stereo chemistry of Walden inversion                                           (4)

 

26. How will you prepare the following from acetoacetic ester?
27. Acetonyl acetone ii) n-butyric acid       iii)  antipyrine
28. 3-methyl 2-pentanone v) Succinic acid
29. Complete the following:
30. Furan + maleic anhydride à ii) Pyrrole + C₆H₅N₂Cl + NaOH à

iii) Quinoline +KMnO₄à                  iv) Pyridine + nC₆H₅Li à

1. Thiophene + H₂SO₄ à
2. a) Explain the following rearrangements with mechanism.             (6)
3. Benzilic acid    ii) Beckmann.
4. b) Write the structure of piperine and give its synthesis. (4)

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc., DEGREE EXAMINATION – CHEMISTRY

THIRD SEMESTER – NOVEMBER 2012

 CH 3502 /4500 – ORGANIC FUNCTIONAL GROUPS – I

 

 

 

Date : 02-11-2012              Dept. No.                                        Max. : 100 Marks

Time : 9.00 – 12.00

 

PART-A

ANSWER ALL THE QUESTIONS:                                                                                     (10×2=20)

1. What is Walden inversion?
2. Arrange the following alkyl halides in the order of decreasing reactivity in S_N1 reaction

RI,  RCl,  RBr,  RF

3. Name the reagents used in the following conversions:
4. a) Ethyl amine into ethyl alcohol b) Acetone into t-butyl alcohol
5. What happens when ethanol is heated with I₂ and NaOH?
6. What are mixed ethers? Give examples.
7. How is anisole prepared from phenol? Give the IUPAC name of anisole.
8. What is Wolf- Kishner reduction?
9. What is crossed Cannizzaro reaction?
10. What is S_Ni reaction?
11. What happens when crotonic acid reacts with HBr?

 

PART-B

ANSWER ANY EIGHT QUESTIONS                                                                             (8×5=40)

 

11. Name the major product obtained when 2-chloro-2-methylbutane is treated with alc. KOH and give reason.
12. Compare the salient features of S_N1 and S_N2 reactions.
13. Explain the mechanism of Reimer-Tiemann reaction.
14. How are 1-propanol and 2-propanol prepared by hydroboration method? Explain why hydroboration violates Markovnikov’s rule.
15. How does phenol differ from aliphatic alcohols?
16. Explain Williamson’s synthesis of ethers.
17. Give reason for the following observations: a) Ethers have low boiling points than isomeric alcohols b) Diphenyl ether cannot be prepared by the dehydration of phenol.

 

18. Account for the following:
19. a) Carbonyl compounds are polar in nature
20. b) –CHO group is meta directing in aromatic electrophilic substitution reactions.
21. Explain the mechanism of conversion of acetaldehyde into β-hydroxybutyric acid.
22. Discuss the mechanism of reaction of benzaldehyde with KCN.
23. Arrange the following acids in the increasing order of acidity and give reason:

acetic acid, fluoroacetic acid, bromoacetic acid,  chloroacetic acid.

22. Give any two methods of preparation of succinic acid. What happens when
23. a) Succinic acid is heated with NH₃ b) Malonic acid is treated with P₂O₅. (3+2)

 

SECTION-C

       ANSWER ANY FOUR QUESTIONS:                                                                      (4×10=40)

 

23. Discuss the effect of the following factors on E1 reaction:
24. a) Structure of alkyl halides b) Strength of the base   c) Polarity of the solvent
25. How is phenol prepared from benzene? How are the following compounds obtained from

phenol?  a) benzene b) picric acid c) azo dye

25. a) How is ethylene oxide prepared? Mention its important synthetic uses.
26. b) Discuss the cleavage reactions of ethers by HI.
27. Discuss the following reactions with mechanism
28. a) Wittig reaction b) Norrish type- I reaction (5+5)
29. a) Discuss the mechanism of Michael addition reaction.
30. b) Discuss the action of heat on dicarboxylic acids.
31. a) Predict the products of the following reactions:
32. i) Acetamide  +  P₂O₅   →
33. ii) Acetyl chloride  +  H₂/ Pd-BaSO₄   →

iii)  Methyl acetate  +  Ethanol  →

1. iv) Adipic acid  +  (CH₂)₆(NH₂)₂   →
2. v) Acetaldehyde  +  malonic ester  →

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