CY5013 : Conceptual Organic Chemistry

Course Objectives: To learn and apply various concepts such as stereochemistry and fundamental principles of stereoselectivity in organic chemistry.

Learning Outcomes: At the end of the course, the learners should be able to:

Comprehend and Predict the role of temperature, solvents, and catalysts in organic reactions Elucidate reaction mechanisms using isotope effects

Identify and differentiate prochirality and chirality at centers, axis, planes and helices and determine the absolute configuration

Evaluate the stability of various conformers of acyclic and cyclic systems using steric, electronic and stereoelectronic effects and correlate them to reactivity. Use various models for determining stereoselectivity of various organic transformations

Course Contents:

Physical organic chemistry: Relationship between thermodynamic stability and rates of reactions – kinetic and thermodynamic control of product formation, Hammond’s postulate, Curtin Hammett principle. Catalysis (acids, bases, and nucleophiles) and isotope effects, importance in the determination of organic reaction mechanisms, solvent effects, examples from SN2 and E2 reactions. Introduction to carbon acids, pKa of weak acids.

Stereochemistry: The concept of prochirality: topicity, prosteroisomerism, stereotopic ligands and faces and stereoheterotopic ligands, introduction to molecular symmetry and chirality, Center of chirality, molecules with C, N, S based chiral centers, axial, planar and helical chirality, stereochemistry and absolute configuration of allenes, biphenyls, binaphthyls, spiranes, exo-cyclic alkylidenecycloalkanes, ansa and cyclophanic compounds.

Conformational analysis: Introduction to conformational analysis, steric, electronic and stereoelectronic effects in governing the conformation of acyclic and cyclic (5 and 6 membered rings) systems, A-strains and anomeric effect, decalins, transannular interactions in medium size rings.

Conformation and reactivity: steric and electronic effects in syn-elimination, E2 elimination and neighboring group participation (Woodward, Prevost methods) of acyclic and cyclohexyl systems, esterification, substitution reaction and formation and opening of epoxide in cyclohexyl systems (Furst Plattner rule).

Stereoselectivity: Classification, terminology, principle of stereoselectivity, examples of diastereoselectivity using Cram, Cram-Chelate, Felkin-Ahn, anti-Felkin, Houk models, Cieplak and cation coordination models, and Zimmerman-Traxler transition

states, enantioselectivity. Desymmetrization and kinetic resolution, methods of determination of absolute configuration.

Text Books:

  1. A. Carey and R. A. Sundberg, Advanced Organic Chemistry, Part A: Structure and Mechanisms, 5th Edition, Springer, New York, 2007.
  2. H. Lowry and K. S. Richardson, Mechanism and theory in organic chemistry, Second edition, , Harper & Row, New York, 1981.
  3. S. Isaacs, Physical Organic Chemistry, , ELBS, Longman, UK, 1987.
  4. J. Kirby, Stereoelectronic effects, Oxford Chemistry Primers, 2011.
  5. Steric and Stereoelectronic Effects in Organic Chemistry, V. K. Yadav, Springer, 2016.
  6. Nasipuri,Stereochemistry of Organic Compounds. Principles and Applications, Second Edition, Wiley Eastern Limited, New Delhi, 1994. Ch.2-6 and 9-12.
  7. G. Morris, Stereochemistry, RSC Tutorial Chemistry Text 1, 2001
  8. L. Eliel and S. H. Wilen, Stereochemistry of Organic Compounds, John Wiley & Sons, New York, 1994.