University of Delhi 2008 B.Sc Chemistry Organic - XVI - Question Paper

1. Answer the subsequent questions:

i) Nucleophillic substitution in pyridine is favoured at position-2. discuss.

ii) Explain the term ‘overtones’ used in IR spectroscopy.

iii) Electrophillic substitution in naphthalene is favoured at position-1. discuss.

iv) What do you understand by isotactic and syndiotactic polymers?

v) Methyl orange is yellow in basic solution but red in acidic solution. discuss.

2.

i) Give the preparation and uses of alizarin.

ii) Describe briefly the relation ranging from colour and constitution.

iii) Write steps for the synthesis of chloroquine.

3.

i) Calculate the wavelenth for :

a) CH3 – CH = CH – CH = CH

ii) How will you distinguish ranging from the subsequent pairs of compounds with the help of IR spectroscopy?

a) Propanal and propanol;

b) Ethanol and diethylether.

iii) A compound with molecular formula C5H12O indicates the subsequent absorptions in NMR:

d 0.9 (t, 3H), 1.2 (s, 6H), 1.5 (q, 2H) and 1.64 (broad s, 1H).

Propose the structure and assign all peaks.

4.

i) Give the synthesis, uses and side effects of the subsequent drugs:
a) Aspirin;
b) Phenacetin.

ii) Explain the folliowing terms with suitable examples:

a) Antibiotics;

b) Antirheumatics.

iii) Electrophillic substitution in furan takes place more readily at position -2. discuss.

5.

i) Explain the subsequent terms:

a) Inhibitors;

b) Elastomers.

ii) What are melamine-formaldehyde resins? Outline their formation and
applications.

iii) Give the mechanism of cationic addition polymerization of propylene.

6. How will you carry out the subsequent conversions:

i) Furan to furoic acid;

ii) O-acetamidotoluene to indole;

iii) Pyridine to 4-amino pyridine;

iv) 2-Phenylethylamine to 1-methyl isoquinoline.

7. Answer the subsequent :

i) Write steps for the preparation of congo red.

ii) What happens when 2-methylnaphthalene is treated with CrO3?

iii) How would you convert 2-nitrobenzaldehyde to phenanthrene?

iv) Give a synthesis of anthracene from 2-methlbenzoyl chloride.

8.

i) How is tropin converted into:

a) 2-Ethylpyridine;

b) Tropilidine.

ii) How is the presence of N-CH3 group established in an alkaloid ?

iii) Give the number of NMR signals in every of the following:

a) 1, 4-dichlorobenzene;

b) Acetylacetone.

Earning:   Approval pending.