LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc.
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DEGREE EXAMINATION –CHEMISTRY
SIXTH SEMESTER – APRIL 2007
CH 6604 – NATURAL PRODUCTS
Date & Time: 20/04/2007 / 9:00 – 12:00 Dept. No. Max. : 100 Marks
PART-A
Answer ALL questions. (10×2=20)
- What happens when naphthalene is treated with ozone?
- How will you synthesise phenanthrene from benzil?
- Write any one example for ring expansion reaction of pyrrole.
- How does thiophene react with mandelic anhydride?
- What are alkaloids? How are they classified?
- How are terpenoids isolated?
- Write any four properties of nicotine.
- What is isoprene rule?
- Write the basic structure of flavone and flavonol.
- What are natural pigments? Give an example.
PART-B
Answer any EIGHT questions. (8×5=40)
- Explain the Hawarth synthesis of naphthalene.
- What happens when the following reagents are treated with pyrrole?
(a) SO2Cl2/ether (b) K2CO3/heat (c) CHCl3/aq.KOH (d) C6H5N2Cl (e) SO3/pyridine
- Write a note on Hofmann’s exhaustive methylation method of degradation of alkaloids.
- Explain the synthesis of piperic acid from catechol.
- What are terpenoids? How are they classified on the basis of the number of isoprene units?
- Write short notes on isolation of essential oils from plants?
- How is camphor synthesized from camphoric acid?
- Give the different products obtained on the oxidative degradation of α-pinene.
- Explain the synthesis of menthol.
- Explain the biological importance of anthocyanines.
- Write a note on carcinogenic hydrocarbons.
- Elucidate the structure of caffeine.
PART-C
Answer any FOUR questions. (4×10=40)
- a) Explain the orbital structure of naphthalene. (5)
- b) Draw the flow chart of isolation of anthracene. Explain. (5)
- Discuss the constitution and importance of nicotine.
- Elucidate the structure of camphor.
- Explain the structure and synthesis of cyanidine chloride.
- Discuss the structure of quercetin.
- Elucidate the structure of uric acid.