F6/UG2/7/A16 Reg. No

St. Joseph’s College of Arts & Science (Autonomous) St. Joseph’s College Road, Cuddalore – 607001 CH614S – ORGANIC CHEMISTRY - IV

Time : 3 hrs

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

I. Choose the correct answer 1. Which is IR inactive a) HF b) H2

c) HCl

d) CO2

2. Find the λmax value of CH3

CH3 C=C CH3

a) 217nm

COCH3

b) 249nm

c) 234nm

d) 224nm

3. Number of fundamental modes of vibration for H2O2 is_________ a) 2 b) 6 c) 5 d) 8 4. The NMR signal for CH3 CH OH CH3 is ___________ a) 3 b) 4 c) 2 d) 5

LiAIH4 5. CH 3CH 2CH 2COOH  ? a) Primary alcohol c) Tertiary alcohol 6. NMR does not distinguish a) Diastereomers c) Conformers

b) Sec. alcohol d) All the above

b) Geometrical isomers d) Enantiomers

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F6/UG2/7/A16

7. Diels Alder reaction is an example for _________ addition a) [4+2] b) [2+2] c) [2+3] d) [8+2] 8. Squaline is a a) Alkaloid c) Carbohydrate

b) Terpenoid d) Protein

9. [2+2] cycloaddition reaction will be ___________ allowed. a) Thermally b) Photochemically c) Both d) Neither 10. Nucleophilic substitution of isoquinoline will occur at position a) 2 b) 1 c) 8 d) 5 II. Fill up the blanks 11. Clemmenson reduction is the reduction of____________ 12. An organic compound which on hydrolysis to give isoprene units is called ____________ 13. Thermal [3,3] – sigmatropic rearrangement of allyl vinyl ether is___________rearrangement. 14. In mass spectrum the high intense peak is ____________ 15. CH3CH2

BH3 CH2  ? OH- ,H 2O2 ,H 2O

III. Match the following 16. Bayer – villiger

-

UV – spectrum

17. Tungsten filament lamp

-

Hydrazine

18. Wolf – Kishner

-

CH3COOOH (peracid)

19. Cope

-

IR- Radiation

20. Zirconium oxide

-

Sigmatropic

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F6/UG2/7/A16

SECTION – B (10X2=20) Answer any TEN Questions 21. How can mass spectrum be employed to find the molecular weight of a compound? 22. The IR spectrum of a compound is often referred to an finger print region. Explian. 23. What are shielding? 24. TMS is used as standard in NMR spectra why? 25. What is the principal different between UV and IR? 26. Interpret the mass spectra of acetone. 27. Discuss about types of fragmentation with suitable examples. 28. Complete the reaction (i) R

C

C

H + [O]

(ii) R

C

C

R + [O]

KMnO4

?

KMnO4

?

29. Find out the product of the following reaction OH

(i)

K2Cr2O7

?

H2SO4, 55O (ii)

R CH

OH

CrO3

R

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?

F6/UG2/7/A16

30. Write the structure of α – pinene and camphor. 31. Define and explain cyclo-addition with suitable example. 32. Define Ingold’s special Isoprene rule? SECTION- C (5X7=35) Answer any FIVE Questions 33. a) Indicate the expected IR spectra of the following compound. (3) (II) CH3CH2OH

CH

(I) CH3 C

b) Calculate the λmax value for the following compounds. (I)

(II) CH2

C

C

CH3

CH3

CH2

CH3

(4) O

C

CH

C

CH3

CH3

34. a) Discuss the important applications of NMR spectra. b) Explain spin – spin coupling.

(3) (4)

35. a) Write the Wood-Ward’s rule for diene. b) Explain the Fragmentation of CH3CH2CH2CH2CHO.

(3) (4)

36. Complete the reactions. (I)

COCH3 H2O

mCPBA

(II) C6H5 CH (III)

?

? LAH

CH CHO

?

DIBAL CH3COCH3

?

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(3)

(2) (2)

F6/UG2/7/A16

37. a) Explain the mechanism of cope – rearrangement. b) Discuss the Structural elucidation of conine.

(3) (4)

38. a) Write the short note on Nucleophilic substitution in pyridine. (3) b) Write a note on Fischer – Indole synthesis. (4) 39. a) How will you synthesis isoquinoline by BischlerNapieralskii method. (4) b) Write the Structure of citral, geraniol and menthol. (3)

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