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to make students familiar about the concepts and applications of pericyclic reactions and
asymmetric organic synthesis.
to give information about the basic principle of enantioselective reactions and
enantiomeric excess determination.
LEARNING OUTCOMES:
The student will be able to
To apply the information about the synthetic applications of asymmetric organic
synthesis
To understand the mechanisms of various pericyclic reactions.
THEORY (45 Hours)
UNIT-I: Pericyclic Reactions-I (11 Hours)
Classification of pericyclic reactions, Molecular orbital and their symmetry properties, molecular
orbitals of ethylene, 1,3-butadiene;1,3,5-hexatriene; allyl system, Woodward-Hoffmann‘s
conservation of orbital symmetry rule; Analysis of pericyclic reactions: FMO approach,
correlation diagrams method and Perturbation of molecular orbital approach. Cycloaddition
reactions: Supra and antra facial additions, 4n and 4n+2 systems, 2+2 additions of ketenes. Diels-
Alder reactions, 1,3-Dipolar cycloaddition and cheletropic reactions, ene reaction, retro-Diels-
Alder reaction, regioselectivity, periselectivity, torque selectivity, site selectivity and effect of
substituents in Diels-Alder reactions. Other Cycloaddition Reactions- [4+6] Cycloadditions,
Allene Cycloadditions
UNIT-II Pericyclic Reactions-II (11 Hours)
Electrocyclic reactions – controtatory and disrotatory motions, 4n, 4n+2, allyl systems secondary
effects. Electrocyclic rearrangement of cyclobutenes and 1,3 cyclohexadienes. Sigmatropic
Rearrangements: H-shifts and C-shifts, supra and antarafacial migrations, retention and inversion
of configurations, detailed treatment of Claisen and Cope rearrangements, fluxional tautomerism,
aza-cope rearrangements, introductions to Ene reactions. Formation of Vitamin D from 7-
dehydrocholesterol, synthesis of citral using pericyclic reaction, conversion of Endiandric acid E
to Endiandric acid A.
UNIT-III Asymmetric synthesis (12 Hours)
Asymmetric synthesis and its need. Basis, principles and strategiesof asymmetric synthesis,
Sources of chiral compounds and methods (I-IV generations) of asymmetric synthesis,
Enantiomeric excess, Analytical methods for enantiomeric excess determination, Asymmetric
synthesis using chiral starting materials: addition to carbonyl compounds (face blocking/
diastereofacial bias, chiral sulfoxides, organometallics, chiral amplification), α-substitution using
chiral enolatesand chiral auxiliaries (SAMP, RAMP, SULTAM, EVANS, MASAMUNE).
UNIT-IV Asymmetric synthesis-II (11 Hours)
Enantioselective and diastereoslective aldol reactions, Asymmetric addition to C-C double bond:
Asymmetric hydrogenation, Enantioselective epoxidation, Enantioselective hydroxylation,
Asymmetric Diels-Alder reaction (use of chiral dienes and dienophiles), Asymmetric
hydroboration of alkenes, Asymmetric enzymatic transformations, oxidation, reduction and
hydrolysis.
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