problem 1)a) Draw the structure of following with numbering:

i) 1.3.7 - Trimethyl xanthene

ii) Pteridine

iii) 2-Benzyl thiazole

iv) 3-Methyl quinoline

v) 4-Propyl indole.

b) prepare in brief electrophilic substitution reaction of five membered, Benzene fused heterocyclic ring system.

problem 2)a) What are diastereomers? Describe with appropriate exs.

b) Draw the Fischer projection of:

i) Meso 2.3-Dibromobutane

ii) 2-Chlorobutane

iii) 2R, 3S-2-Chlorobutanol.

c) What is racemic resolution ? Describe with appropriate exs the various methods used

problem 3) Answer the following:

a) Trans 1, 2-dimethyl cyclohexane is more stable than its C is isomer. Why?

b) Describe cyclohexane is more stable in chair form than boat form.

c) describe:

i) Staggered and eclipsed

ii) Fischer projection formula.

d) Define the enantiomerism. Provide its pharmaceutical significance.

e) What are proteins? describe its structure.

f) Give the advantage of Z/E nomenclature over cis and trans with ex.

g) What are stereoselective and stereospecific reactions ? Give suitable exs.

problem 4) Answer the following:

a) Describe in brief conformation of n-butane.

b) prepare a detailed note on Racemic modification.

c) Indicate more stable and least stable chair conformation of di-substituted cyclohexane.

d) What is combinatorial chemistry? Give the strategies used in Deconvolution method.

e) What are amino acids ? describe different methods of synthesis of amino acid.

problem 5)a) Give the scheme of retrosynthesis of:

i) Propronolol

ii) Ciprofloxacin.

b) describe in short in about:

i) Solid supported synthesis

ii) Thiazole synthesis.