M.Sc.I, Sem.I, Organic Chemistry(Paper II)


M. Sc.-I (Semester-I)
Organic Chemistry-I (Paper-II)
Unit –I
(a) Reaction mechanism: Structure and reactivity (7)
Types of reactions, strength of acids and bases. Generation, structure, stability and reactivity of reaction intermediates: Carbocations, carbanions, free radicals, carbenes, nitrenes, benzynes and ylides. Effect of structure on reactivity: resonance, steric, hyperconjugation effects.
(b) Aliphatic Nucleophilic substitutions: (8)
The SN2, SN1 and SNi with respect to mechanism and stereochemistry. Nucleophilic substitutions at an allylic, aliphatic trigonal, benzylic, aryl and vinylic carbons. Reactivity effect of substrate structure, effect of attacking nucleophiles, leaving groups and reaction medium. SN reactions at bridged head carbon, competition between SN1 and SN2, ambident nucleophiles, Neighbouring Group Participation.

Unit - II
(a) Aromatic Electrophilic Substitutions: (8)
Introduction, the arenium ion mechanism, orientation and reactivity in Nitration, Sulphonation, Friedel-Crafts and Halogenation in monosubstituted aromatic systems, energy profile diagrams. The ortho / para ratio, ipso attack, orientation in other ring systems (naphthalene, anthracene, 5 and 6 membered aromatic heterocyclic compounds). Diazo-coupling, Vilsmeir reaction, Gatterman-Koch reaction. Nucleophilic aromatic substitution reactions SN1 ,SN2 and Arynes.
(b) Addition to Carbon–Carbon Multiple Bonds (7)
Mechanism and stereochemical aspects of the addition reactions involving electrophiles, nucleophiles and free radicals, regio-and chemo – selectivity, orientation and reactivity. Hydrogenation of double, triple bonds and aromatic rings. Michael reaction. Sharpless asymmetric epoxidation.

Unit - III
(a) Elimination Reactions: (8)
The E1, E2 and E1cB mechanisms. Orientation in Elimination reactions. Hofman versus Saytzeff elimination. Reactivity: effects of substrate structures , attacking base, the leaving group, the nature of medium on elimination reactions, competition between substitution and elimination reactions, pyrolytic elimination reactions.
(b) Rearrangements: (7)
Study of following rearrangements with mechanism and stereochemistry: Beckman, Fries, Hoffman, Schmidt, Curtius , Lossen, Claisen, Benzilic acid, Wolff, Steven’s & Sommelet-Hauser.

Unit – IV
Stereochemistry: (15)
Isomerism, classification of isomers ( constitutional and stereoisomers). Concept of Chirality: Recognition of symmetry elements and chiral structures, Prochiral relationship. Racemic modifications and their resolution. R and S nomenclature. Geometrical isomerism E and Z nomenclature., Erythro and Threo nomenclature, Conformational analysis of mono and isubstituted cyclohexanes ( stability and reactivity ), representation of conformational isomers.

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