pdusu previous year paper M.Sc(Previous) examination 2019
M.Sc(Previous) examination 2019
paper II
Organic Chemistry
Explain briefly the following with suitable examples:
(1) Optical activity in biphenyles
(H) Conformational analysis of cycloalkanes
(ii) Effect of conformation on reactivity
(iv) Stereochemistry of the compounds containing
3. (a) Elaborate the application of Taft equation.
(b) Briefly explain the transition state and intermediate with suitable examples
(c) Discuss the structure, stability of carbenes. Give two important reactions involving carbenes with their mechanism
(1) Norbormyl system
(i) Nucleophilic substitution at allylic position
( 2 ) Ambident nucleophiles
(3 ) Regioselectivity
Unit-IIl
5 (a) Explain the factors affecting reactivity of aliphatic electrophilic subatitution reactions
(b) Complete the following reactions
(b) Briefly discuss the following:
1 Regio and chemoselectivity
2 Orientation and reactivity
Unit-'V'
Write short notes on the following:
1,3-dipolar cycloaddition
(1) Claisen Rearrangement
(ii) Cope Rearrangement
(a) Explain the suprafacial and antrafacial shift of H.
5. (b) Draw correlation diagram for the cycloaddition of two ethylene molecules.
(c) What are pericyclic reactions? Drawing correlation alagram discuss disrotatory and conrotatory interconversion of cyciobutene and butadiene