Organic Reactions and Their Mechanisms — P S Kalsi (3rd Edition)
P S Kalsi's Organic Reactions and Their Mechanisms has quietly become one of those reference texts Indian chemistry students keep returning to. Now in its third edition, the book sits at a useful intersection—detailed enough for postgraduate study, yet approachable for undergraduates who are still building their confidence with arrow-pushing and reaction logic.
Kalsi brings serious academic weight to the subject. Formerly Dean of Colleges at Punjab Technical University, Jalandhar, and Professor & Head of Chemistry at the College of Basic Sciences and Humanities, Punjab Agricultural University, Ludhiana, he writes with the patience of someone who has taught these topics across decades. The explanations reflect that classroom experience—mechanisms are broken into steps, and each chapter ends with problems followed by worked answers, so the self-learner rarely feels stranded.
What Makes This Book Stand Out
The book spans 17 chapters and nearly 700 pages. It opens with foundational ground—structure and bonding, electronegativity, inductive and field effects, the Hammett and Taft equations—before moving into delocalized bonding, aromaticity, and acid–base behaviour. From there, the treatment grows progressively more applied. Readers move through nucleophilic substitution, common organic reactions, named reagents, and electrophilic as well as nucleophilic aromatic substitution. Later chapters handle photochemistry, additions, eliminations, oxidation and reduction methods, molecular rearrangements, free radical reactions, and pericyclic reactions. That last chapter, running almost eighty pages, is among the most thorough single-textbook treatments of pericyclic chemistry you'll find at this level.
A standout feature is the book's name-reaction coverage. The index alone lists over seventy named reactions—from the Aldol and Claisen condensations to the Diels–Alder, Heck, Mitsunobu, and Wittig-type transformations—each discussed with its mechanism rather than just named in passing. A dedicated reagents section does the same for the tools a synthetic chemist actually reaches for: Grignard reagents, LDA, PCC and PDC, DCC, DMSO-based oxidations, borane and Selectride reducing agents, Wilkinson's catalyst, and many others. For students preparing for competitive exams, this density of named reactions in one place is genuinely useful.
Chapter Index at a Glance
| Ch. | Title | Pages |
|---|---|---|
| 1 | Fundamental Principles and Special Topics | 1–38 |
| 2 | Delocalized Chemical Bonding | 39–86 |
| 3 | Organic Acids and Bases | 87–121 |
| 4 | Organic Reactions and the Determination of their Mechanisms | 122–175 |
| 5 | Aliphatic Nucleophilic Substitution and its Synthetic Applications | 176–215 |
| 6 | Common Organic Reactions and their Mechanisms | 216–262 |
| 7 | Reagents in Organic Synthesis and Relevant Name Reactions | 263–328 |
| 8 | Electrophilic Aromatic Substitution | 329–365 |
| 9 | Aromatic Nucleophilic Substitution | 366–379 |
| 10 | Photochemistry | 380–420 |
| 11 | Addition to Carbon-Carbon and Carbon-Hetero Multiple Bonds | 421–437 |
| 12 | Elimination Reactions | 438–461 |
| 13 | Oxidation Methods | 462–499 |
| 14 | Reduction Methods | 500–542 |
| 15 | Molecular Rearrangements | 543–568 |
| 16 | Free Radical Reactions | 569–604 |
| 17 | Pericyclic Reactions | 605–682 |
| — | References and Further Reading | 683–684 |
| — | Index | 685–693 |
Who Should Read This
Who is this for? The intended audience is broad. B.Sc. students will find the early chapters and problem sets align closely with university syllabi, while M.Sc. learners benefit from the advanced coverage of pericyclic reactions and rearrangements. CSIR-NET and GATE aspirants can treat it as a mechanism-focused revision resource, since the book repeatedly reinforces the logic of electron movement rather than asking readers to memorize outcomes in isolation. BITSAT candidates covering organic chemistry will also find the reaction sections relevant, though the depth here goes well beyond what that exam demands. With only very minor changes, the content maps onto the syllabi of nearly all Indian universities.
A few practical notes. The book uses standard IUPAC conventions, subscripts and superscripts for mechanistic notation (SN1, SN2, E2, and so on), and includes reaction profile diagrams and Jablonski diagrams where they aid understanding. Each chapter carries its own problem set with solutions, which makes the text well-suited to self-study as much as classroom teaching.
If you are looking for a single organic chemistry resource that takes mechanism seriously—without burying the reader in unreadable detail—this third edition earns its place on the shelf.
Download the Book
Grab your copy directly from the link below.
⬇ Download PDF — Organic Reactions and Their Mechanisms