A2P1/19N15 Reg. No

St. Joseph’s College of Arts & Science (Autonomous) St. Joseph’s College Road, Cuddalore – 607001 PCH805 – ORGANIC CHEMISTRY - II

Time : 3 hrs

Max Marks :75 SECTION – A (20X1=20) Answer ALL Questions

I. Choose the correct answer 1. The order of probability of SN1 among the following halides is H3C-x, R-CH2-x I II R R

R CH-X

C - X

R IV

R III

, a) IV>II>III>I c) IV>III>II>I

b) I>II>III>IV d) III>II>IV>I

2. Anchimeric assistance is due to a) Neighbouring group participation c) Substrate effect 3. The electrophile used in epoxidation is a) NO2+ b) SO3 c) R+

b) Solvent effect d) Isomeric effect

d) Peracid

4. Hofmann rule is applicable to those substrates in which the departing nucleophilic group is a) Sulphonium b) Quartenary Ammonium c) Oxonium d) All of the above

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A2P1/19N15 5. Benzyne reacts with furan to give ________ a) α-naphthol b) Furfural c) 1-phenylfuran d) 2-phenyl furan 6. The reagent used in chichibabin reaction is _______ a) NaNH2/NH3 b) NH3 c) C6H5NH2 d) CH3NH2 7. Dieckmann reaction results in a) Cyclic α-ketones c) Cyclic γ –Ketones

b) Cyclic β-ketones d) Cyclo alkanes

8. The metal catalyst used is Reformatsky reaction is a) mg b) Na c) Al d) Zn

9. The electrophile used in nitration of benzene is a) NO2+ b) NO c) N2 d) NO3 10. Anthracene during Vilsmeier-Haack reaction gives _______ a) 9-Anthraldehyde b) 10-Anthraldehyde c) 1-Anthraldehyde d) 2-Anthraldehyde II. Fill up the blanks 11. ∝-alkylation of ketone is _______

12. Neomenthyl xanthate on chugaev reaction gives mainly _______ 13. Benzaldehyde during stobbe reaction gives _______ 14. The electrophile in Reimer Tiemann reaction is _______ 15. Phthaloyl peroxide generates benzyne intermediate via _______ III. Match the following 16. Hvz reaction

- Electrophile

17. Borane

- Formylation of aromatic ring

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A2P1/19N15 18. Perkin condensation

- α-halo carboxylic acid

19. Vilsmier -Haack reaction

- Resonance stabilization

20. Benzyl halide

-α,β - unsaturcted aromatic acid SECTION – B (10X2=20) Answer any TEN Questions

21. Give the order of reactivity of alkyl halide towards SN2 and explain. 22. Nucleophilic substitution at bridgehead system is slow. Why? 23. Define saytzeff rule? 24. What is the stereochemical requirement in E2 elimination in cyclohexane system? 25. What is Dickmann reaction? 26. Trans-2-halogeno cyclohexyl-brosylate reacts faster than its cis-isomer. Why? 27. Give the hydration reaction of substituted alkynes. 28. What is Mannich reaction? 29. What is Reimer-Tiemann reaction? 30. Give any two electrophilic substitution reactions of furan. 31. Give any two methods of generation of benzyne intermediate. 32. What is chichibabin reaction?

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A2P1/19N15 SECTION –C (5X7=35) Answer any FIVE Questions 33. Explain Neighbouring group participation in nucleophilic substitution reaction. 34. a) Give the mechanism of cope elimination. b) Explain Hofmann’s rule in E2 elimination.

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35. Explain hydroboration with an example. 36. What is Benzoin condensation? Give the mechanism of it. 37. a) What is stobbe reaction? Give the mechanism of it. b) Give the mechanism of wittig reaction

(4) (3)

38. a) Write any four electrophilic substitution reaction of thiophene(4) b) Give the mechanism of vilsmeier-Huck reaction. (3) 39. Explain aromatic nucleophilic substitution through benzyne intermediate.

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