Q10/15B/03-14 Reg. No

St. Joseph’s College of Arts & Science (Autonomous) St. Joseph’s College Road, Cuddalore – 607001 PCH1013 - ORGANIC CHEMISTRY – IV

Time : 3 hrs

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

I. Choose the best answer 1. Morphine contains ----------- rings. a) 4 b) 5 c) 3

d) 6

2. The base that pairs with guanine is a) Cytosine b) Thymine c) Thiamine

d) Adenine

3. The solid-phase peptide synthesis was proposed by a) Sanger b) Pauling c) Edman d) Merrifield 4. The C-terminal amino acid in the following tripeptide is : Gly-AlaPhe a) Glycine b) Glutamic acid c) Alanine d) Phenylalanine 5. The reagent used for Alcohol protection is a) Me3SiCl b) Me2CO c) MeCO2H

d) Glycol

6. Phosphorus ylids are used to synthesis ------------. a) Alkanes b) Alcohols c) Alkynes

d) Alkenes

7. The reagent which corresponds to the following synthon is:

+

CO2H Br

OH a)

b)

c) OH

d) Br

~1~

CO2H

CO2H

Q10/15B/03-14

8. The following reaction is an example of O

NH2

NH2

a) Substitution c) Functional group interconversion

b) Addition d) Rearrangment

9. The heterocycle having one nitrogen atom and one oxygen atom in the ring is a) Oxazole b) Imidazole c) Thiazole d) Isoflavone 10. The following is a purine a) Uracil b) Thymine

c) Cytosine

II. Fill in the blanks 11. ------------ base is present only in DNA. 12. ----------- is a C-terminal protecting group. 13. Quaternary ammonium salts are used as -------------. 14. The final product in retrosynthesis is called ------------. 15. The structure of thiazole is --------------. III. Match the following 16. Reserpine

A. Cysteine

17. Inactive Amino acid

B. Vitamin A1

18. Reformatsky reaction

C. Bond breaking

19. Umpolung

D. Alkaloid

20. Disconnection

E. Glycine F. 1,3-Dithiane

~2~

d) Adenine

Q10/15B/03-14

SECTION - B (10X2=20) Answer any TEN Questions 21. Draw the structure of cocaine. 22. Mention the functions of DNA. 23. Give the synthesis of the tripeptide Phe-Val-Ala. 24. What is the secondary structure of proteins? 25. Suggest suitable mechanism for Stork enamine reaction. 26. What is the advantage of microwave synthesis over ordinary synthesis? 27. Give any two reactions of 9-BBN. 28. Define a synthon. 29. Show the disconnection for the following structure: O

O Ph

30. Outline a synthetic route for Pentan-2,4-dione. 31. Illustrate the synthesis of imidazole. 32. How will you convert Cholesterol to estrone? SECTION - C (5X7=35) Answer any FIVE Questions 33. a) Give the last two steps of quinine synthesis b) Mention the outline for biosynthesis of Cholesterol. c) List the types of RNA.

~3~

(2) (3) (2)

Q10/15B/03-14

34. a) What is a tetrapeptide? Give an example. b) Discuss Merrifield synthesis. c) How will you determine the tertiary structure of protein?

(2) (3) (2)

35. a) List any two uses of DIBAL b) How will you protect and deprotect Aldehydes? c) Suggest mechanism for Robinson annulation.

(2) (2) (3)

36. a) How will you synthesize 1-bromo-3-methylbut-2-ene? (3) b) Illustrate the disconnection and synthons for the following molecule: (2) OH

CHO

c) Explain Retro Diels-Alder reaction.

(2)

37. a) Discuss the synthesis of cytosine. b) How will you effect the conversion of cholesterol to testosterone? c) What are anthocyanins? Give examples.

(3)

38. a) Give the structure of Adenine. b) Predict the product of the following reaction:

(2) (3)

(2) (2)

O

Ph3P=CHCO2Et

?

c) What do you mean by logical disconnections? 39. a) What are active methylene compounds? How will you alkylate it? b) Illustrate any two reactions of sulfur ylids. c) Give the synthesis of Vitamin A1.

***********

~4~

(2)

(3) (2) (2)