Mechanistic aspects of Hydrocarbons

Paper Code: 
CHY 112
Contact Hours: 
Max. Marks: 

Course Objectives:

This course will enable the students to

1. make the students understand the core concepts of organic chemistry i.e. resonance, hyperconjugation, inductive effect etc. and their qualitative and quantitative treatment.

2. provide an in-depth knowledge about alkanes, cycloalkanes, alkenes & alkynes and their reactivity.

Course Outcomes (COs):


Learning outcomes

(at course level)

Learning and teaching strategies



Paper Code

Paper Title









Mechanistic aspects of Hydrocarbons

The students will be able to –


CO7: identify different electronic effects and differentiate their role and impacts in a particular situation. CO8: describe the structure, stability and reactivity and mechanistic ability of various hydrocarbons

CO9: learn and identify many organic reaction mechanisms including free radical substitution, electrophilic and nucleophilic addition.

CO10: predict the products of different hydrocarbons with different reagents


Traditional chalk & board method with interactive lectures


Group discussions


Question preparation


Subjective type


Long answer


Short answer


Objective type


Multiple choice questions


One answer/two answer type questions


Assertion and reasoning

The oral and written examination s (Scheduled and surprise tests)


Problem solving exercises






Semester End Examination



Unit I: 
General treatment of reaction mechanism

Mechanistic classification: Ionic, radical and pericyclic; heterolytic bond cleavage and heterogenic bond formation, homolytic bond cleavage and homogenic bond formation; representation of mechanistic steps using arrow formalism. Reactive intermediates: generation and stability (brief idea) ofcarbocations- Classical and nonclassical, carbanions, free radicals, carbenes, nitrenes.

Unit II: 
Chemistry of Alkanes & Cycloalkanes
Chemistry of alkanes: Formation of alkanes,chemical reactions with special reference to free radical substitutions: bond dissociation energies, halogenation - relative reactivity and selectivity.
Chemistry of cycloalkanes: Types, methods of synthesis, chemical reactions
 Baeyer strain theory, Theory of strainless ring.
Unit III: 
Chemistry of Alkenes

Hybridization of carbon, cis-trans isomerism, IUPAC nomenclature, general methods of preparation, physical properties. Structure and bonding in alkenes, methods of synthesis and chemical reactions, Mechanism of E1, E2, E1cB reactions(a brief idea). Saytzeff and Hoffmann eliminations. Electrophilic additions and their mechanisms (Markownikoff/Anti Markownikoff addition), mechanism of oxymercuration-demercuration, hydroboration-oxidation, ozonolysis, reduction (catalytic and chemical), syn and anti hydroxylation (oxidation). Addition of singlet and triplet carbenes, Regioselectivity.

Unit IV: 
Chemistry of Dienes

Structure and stability of conjugative and cumulative dienes, resonance and molecular orbital structure of allene and 1,3-butadiene; methods of preparation, addition of hydrogen halides to conjugated dienes – 1,4 v/s 1,2 addition (formation, structure and stability of allylic carbocation and free radicals).An elementary concept of orbital symmetry & it’s application to  Diels-Alder reaction. Allylic and benzylic bromination.

Unit V: 
Chemistry of Alkynes

Nomenclature, Formation and reactions of alkynes,structure & stability, acidity, electrophilic and nucleophilic additions. Hydration to form carbonyl compounds, alkylation of terminal alkynes, reduction of alkynes –catalytic hydrogenation, dissolving metal reduction.

Essential Readings: 
  • Organic Chemistry; Fourth Edition, Indian Edition; G. Marc Loudon; Oxford University Press, New York,2008.
  • Organic Chemistry; Sixth Edition; G. Marc Loudon, J. Parise; WH Freeman, New York, 2015.
  • Organic Chemistry; Seventh Edition; R. T. Morrison, R. N. Boyd, S.K. Bhattacharjee; Pearson Education India, New Delhi, 2010.
  • Reaction Mechanism in Organic Chemistry; Third Edition; S.M. Mukherjee and S.P. Singh; Laxmi Publications, New Delhi, 2007.
Academic Year: